Answer:
[tex]T_F=47.3\°C[/tex]
Explanation:
Hello!
In this case, since we have hot and cold water, we infer that as hot water cools down, cool water heats up based on the first law of thermodynamics; thus, we can write:
[tex]Q_{hot}+Q_{cold}=0[/tex]
In such a way, we can write the expression in terms of mass, specific heat and temperature change:
[tex]m_{hot}C_{hot}(T_F-T_{hot})+m_{cold}C_{cold}(T_F-T_{cold})=0[/tex]
However, since they both have the same specific heat and the same mL are in g due to the 1.00-g/mL density, we obtain:
[tex]m_{hot}(T_F-T_{hot})+m_{cold}(T_F-T_{cold})=0\\\\T_F=\frac{m_{hot}T_{hot}+m_{cold}T_{cold}}{m_{hot}+m_{cold}}[/tex]
Now, we plug in to obtain:
[tex]T_F=\frac{140.0g*95.00\°C+300g*25.00\°C}{140.0g+300g}\\\\T_F=47.3\°C[/tex]
Best regards!
Potassium nitrate (KNO3) is a water-soluble white powder that
is often used as a plant fertilizer. What is the molar
concentration of a solution made up of 505 grams of
potassium nitrate mixed with 250 mL water? The molar mass
of KNO3 is 101.1 g/mol. Round your answer to 3 sig figs.
The molar concentration, often called molarity, describes how much of a substance (a solute) is present per unit of solvent. By definition, the molar concentration (M) is equal to the number of moles (n) of solute divided by the number of liters (the volume, or V) of the solution.
Here, your solute is potassium nitrate, or KNO3. You're given the mass of KNO3 (505 g), but you need to convert this quantity to moles before you can find the molarity. To go from mass to moles, simply divide the mass of the substance by its molar mass (given to you as 101.1 g/mol).
[tex]505 \text{ g KNO}_\text{3} \div 101.1 \text{ g KNO}_3/\text{mol KNO}_{3} = 4.995 \text{ mol KNO}_3[/tex]
Now that we have the moles of solute, we divide by the liters of solution. We're given the volume of solution in milliliters, so to convert to liters, simply divide by 1000 (1 L = 1000 mL, so 1 mL = 1/1000 mL). Our volume of solution is thus 0.250 L.
Finally, we can calculate the molar concentration of the KNO3 solution:
[tex]4.995 \text{ mol KNO}_{3 }\div 0.250 \text{ L} = 19.98 \text{ }\frac{\text{moles}}{\text{liters}}\text{ of KNO}_3[/tex]
But, we're told to round our answer to three sig figs. Thus, our rounded and final answer would be 20.0 moles/liters of KNO3.
09. Where does Mitosis take place? I
where growth and repair are happening
in your hair cells only
in your blood cells only
Answer:
In plants mitosis takes place throughout life in growing regions called the meristems. Replacements as cells wear out. The cells of the skin and bone marrow are sites of active mitosis replacing skin cells and red blood cells that only have a limited life. Repair.
Explanation:
If one DNA strand reads CCGTAATGCAT, what will be the sequence of the complementary
strand?
Si una hebra de ADN lee CCGTAATGCAT, ¿cuál será la secuencia de la hebra
complementaria?
Write your answer here:
Escriba su respuesta aquí:
a) CCGTAATGCAT
b) GGCATTACGTA
c) CCGATTAGCTA
d) GGCTAATCGAT
If one DNA strand reads CCGTAATGCAT, the sequence of the complementary strand will be - b) GGCATTACGTA
Complementary base pairingThe nucleic acid sequence of bases can form a double-stranded structure by matching base pairs.Adenine matches with thymine (uracil in RNA) and vice versaGuanine matches with cytosine and vice versaFor example, the complementary sequence to C-A-T-G (where each letter stands for one of the bases in DNA) is G-T-A-C.So, DNA strand - C-C-G-T-A-A-T-G-C-A-T
Complementary DNA strand - G-G-C-A-T-T-A-C-G-T-A
Thus, If one DNA strand reads CCGTAATGCAT, the sequence of the complementary strand will be - b) GGCATTACGTA
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2. Describe briefly of some ways these organisms might interact with
each other. (5 points)
The level of a liquid (i.e. distilled water) in laboratory glassware is determined by sight. The level corresponds to a specific volume. The volume is established by identifying the meniscus of the liquid relative to a calibration mark or series of calibration marks on the glassware (i.e. volumetric flask vs. buret). Which of the following statements is NOT correct when reading the meniscus?
a. the edge of the meniscus should be used to determine volume relative to the mark or marks
b. the meniscus should be read at eye level
c. when the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
d. the center of the meniscus should be used to determine volume relative to the mark or marks
Answer:
c. when the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
Explanation:
When we put a liquid in a pipette, we can see that the surface of that liquid will have a curve. This curve is called the meniscus and it has the correct volume that an aqueous solution has. However, for this, it is necessary that the meniscus is observed at eye level and that its edges and center are clearly visible.
What type of energy does a bouncing ball have ?
Answer:
Kinetic
Explanation:
When the ball is falling towards the table, it has kinetic energy. This elastic potential energy is why the ball is able to bounce, or rebound. After the ball rebounds, the elastic potential energy is transformed into kinetic energy, but it will never possess as much kinetic energy as during its original fall.
Answer:
Explanation:
It has kinetic energy.
Hope it helped you.
A mixture of krypton and argon gas is compressed from a volume of to a volume of , while the pressure is held constant at . Calculate the work done on the gas mixture. Be sure your answer has the correct sign (positive or negative) and the correct number of significant digits.
Answer:
42556.5 J
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
A mixture of krypton and neon gas is compressed from a volume of 96.0L to a volume of 68.0L , while the pressure is held constant at 15.0atm . Calculate the work done on the gas mixture. Be sure your answer has the correct sign (positive or negative) and the correct number of significant digits.
The workdone on the gas can be calculated using below expresion,
W = - PΔV
Where P= Pressure of the mixture of the given gases
ΔV = Change in volume
Given;
Initial volume of the mixture= 96.0L
= 96.0L/ 1000= 0.096m³
Final volume of the mixture= 68.0L
= 68.0L/1000= 0.068m³
Pressure= 15.0atm, but we need to convert to N/m² for unit consistency.
1 atm= 101325 N/m²
15 atm = X
Cross multiply
X = (15×101325 )
X= 1519875 N/m²
P= 1519875 N/m²
W = - PΔV
W= - 1519875 × (0.068 - 0.096)
= - 1519875 × -0.028 m³
W= 42556.5 J
What is a net ionic equation?
A. An equation that shows all substances as compounds
B. An equation that is balanced on both sides
C. An equation showing only what is involved in the reaction
D. An equation that shows all dissolved compounds as ions
Answer:
I think it will option D hope it helps
Which of the following would be produced when two or more different atoms bond chemically?
O A. compounds
.
B. elements
C. solutions
D. mixtures
Answer:
When two or more atoms chemically bond with each other, the resultant chemical structure is a molecule. The familiar water molecule, H2O, consists of two hydrogen atoms and one oxygen atom; these bond together to form water, irdk but it's either C or D
Explanation:
hope this helps have a good rest of your day :) ❤
5. Calcium carbide (CaC2) reacts with water, producing acetylene (C2H2): CaC2 + 2H2O -> Ca(OH)2 + C2H2
Production of 13g of C2H2 requires __________ g of H2O. a. 4.5 b. 9.0
c. 18 d. 4.8 x 102 e. 4.8 x 10-2
Answer: c
Explanation:
18
Answer:
17.99 g H2O
Explanation:
13 g C2H2(1 mol C2H2/26.04 g C2H2)(2 mol H2O/1 mol C2H2)(18.02 g H2O/1 mol H2O) = 17.99 g H2O used up
There are
molecules of carbon dioxide (CO2) in 102.5 grams.
Answer:
1.403x10²⁴ molecules
Explanation:
In order to calculate how many molecules of CO₂ are there in 102.5 g of the compound, we first convert grams to moles using its molar mass:
102.5 g ÷ 44 g/mol = 2.330 mol CO₂Now we convert moles into molecules using Avogadro's number:
2.330 mol * 6.023x10²³ molecules/mol = 1.403x10²⁴ moleculescan energy transfer even if the objects are in the same temprature
Answer:
Yes
Explanation:
The rate constant (k) for a reaction was measured as a function of temperature. A plot of ln k versus 1>T (in K) is linear and has a slope of -1.01 * 104 K. Calculate the activation energy for the reaction.
Answer:
8.397J/mol is the activation energy for the reaction
Explanation:
The graphical form of Arrhenius equation is:
ln k = -Ea/R*(1/T)+lnA
Where k is activation energy
Ea is activation energy
R is gas constant (8.314J/molK)
T is absolute temperature
And A is the pre-exponential factor.
The slope of the plot is -Ea/R:
-Ea/R = -1.01x10⁴K
-Ea/8.314J/molK = -1.01x10⁴K
Ea = -1.01x10⁴K*8.314J/molK
Ea = 8.397J/mol is the activation energy for the reaction
What type of tide would this arrangement of earth-moon-sun create?*
O full moon tide
O neap tide
O new moon tide
Ospring tide
HURRY!!!
Answer:
neap tide
Explanation:
There are two different types of tides, which are the spring tide and the neap tide.
Neap tides are weak tides which occur when the gravitational forces of the sun and the moon are at right angles to each other with respect to the earth. Since the sun and moon are at right angles, it causes a difference between the low and high tide.
The spring tide are strong tides which occur when the moon, sun and earth are in straight line. The spring tide occur during full moon and new moon.
Answer:
Neap Tides
The result is a neap tide. The same effect happens during third quarter. These occur during first and last quarter moons. The gravitational pull is not as strong.
Explanation:
the first answer is correct
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide? (Use molar masses)
Answer:
Formulas
3.2 Determining Empirical and Molecular Formulas
Learning Objectives
By the end of this section, you will be able to:
Compute the percent composition of a compound
Determine the empirical formula of a compound
Determine the molecular formula of a compound
The previous section discussed the relationship between the bulk mass of a substance and the number of atoms or molecules it contains (moles). Given the chemical formula of the substance, one may determine the amount of the substance (moles) from its mass, and vice versa. But what if the chemical formula of a substance is unknown? In this section, these same principles will be applied to derive the chemical formulas of unknown substances from experimental mass measurements.
Percent Composition
The elemental makeup of a compound defines its chemical identity, and chemical formulas are the most succinct way of representing this elemental makeup. When a compound’s formula is unknown, measuring the mass of each of its constituent elements is often the first step in the process of determining the formula experimentally. The results of these measurements permit the calculation of the compound’s percent composition, defined as the percentage by mass of each element in the compound. For example, consider a gaseous compound composed solely of carbon and hydrogen. The percent composition of this compound could be represented as follows:
%H=mass Hmass compound×100%
%C=mass Cmass compound×100%
If analysis of a 10.0-g sample of this gas showed it to contain 2.5 g H and 7.5 g C, the percent composition would be calculated to be 25% H and 75% C:
%H=2.5g H10.0g compound×100%=25%
%C=7.5g C10.0g compound×100%=75%
EXAMPLE 3.9
Calculation of Percent Composition
Analysis of a 12.04-g sample of a liquid compound composed of carbon, hydrogen, and nitrogen showed it to contain 7.34 g C, 1.85 g H, and 2.85 g N. What is the percent composition of this compound?
Solution
To calculate percent composition, divide the experimentally derived mass of each element by the overall mass of the compound, and then convert to a percentage:
%C=7.34g C12.04g compound×100%=61.0%%H=1.85g H12.04g compound×100%=15.4%%N=2.85g N12.04g compound×100%=23.7%
The analysis results indicate that the compound is 61.0% C, 15.4% H, and 23.7% N by mass.
Check Your Learning
A 24.81-g sample of a gaseous compound containing only carbon, oxygen, and chlorine is determined to contain 3.01 g C, 4.00 g O, and 17.81 g Cl. What is this compound’s percent composition?
ANSWER:
12.1% C, 16.1% O, 71.8% Cl
Determining Percent Composition from Molecular or Empirical Formulas
Percent composition is also useful for evaluating the relative abundance of a given element in different compounds of known formulas. As one example, consider the common nitrogen-containing fertilizers ammonia (NH3), ammonium nitrate (NH4NO3), and urea (CH4N2O). The element nitrogen is the active ingredient for agricultural purposes, so the mass percentage of nitrogen in the compound is a practical and economic concern for consumers choosing among these fertilizers. For these sorts of applications, the percent composition of a compound is easily derived from its formula mass and the atomic masses of its constituent elements. A molecule of NH3 contains one N atom weighing 14.01 amu and three H atoms weighing a total of (3 × 1.008 amu) = 3.024 amu. The formula mass of ammonia is therefore (14.01 amu + 3.024 amu) = 17.03 amu, and its percent composition is:
%N=14.01amu N17.03amuNH3×100%=82.27%%H=3.024amu H17.03amuNH3×100%=17.76%
This same approach may be taken considering a pair of molecules, a dozen molecules, or a mole of molecules, etc. The latter amount is most convenient and would simply involve the use of molar masses instead of atomic and formula masses, as demonstrated Example 3.10. As long as the molecular or empirical formula of the compound in question is known, the percent composition may be derived from the atomic or molar masses of the
Which natural resource is limited in supply?
)
A)
wind
B)
petroleum
C)
water power
D)
solar energy
Strontium metal reacts with aluminum chlorate to produce strontium
chlorate and aluminum metal. Identify the type of reaction, then write a
complete balanced chemical equation for the reaction. If no reaction
occurs, explain why. (2 points)
Answer: single replacement reaction, [tex]3Sr+2Al(ClO_3)_3\rightarrow 3Sr(ClO_3)_2+2Al[/tex]
Explanation:
A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.
A general single displacement reaction can be represented as :
[tex]XY+Z\rightarrow XZ+Y[/tex]
As strontium metal is added to aluminum chlorate , strontium being more reactive than aluminium, displaces aluminium atom its salt solution and lead to formation of strontium chlorate and aluminum metal.
[tex]3Sr+2Al(ClO_3)_3\rightarrow 3Sr(ClO_3)_2+2Al[/tex]
During life body pH is ___ shortly after death the pH becomes ___ after time the pH becomes ___. (A) Acidic, neutral, basic (B) Neutral, acidic, basic (C) Neutral, basic, acidic (D) Acidic, acidic, basic
A solution contains a mixture of pentane and hexane at room temperature. The solution has a vapor pressure of 263 torr. Pure pentane and hexane have vapor pressures of 425 torr and 151 torr, respectively, at room temperature.
Required:
What is the mole fraction of hexane?
Answer:
Xb = 0.59
Explanation:
Let's analyze the given data.
We have a total vapor pressure of 263 Torr for the mix of the two gases. And the individual vapour pressures for each gas is given, and it's 425 Torr for pentane and 151 Torr for hexane.
We are asked to determine the mole fraction of hexane. For practical purposes, we will label pentane as "a" while hexane would be "b". So, let's write the equations that we need to calculate this.
We know that the total pressure of a solution would be:
P = Pa + Pb (1)
And we also know that these individual pressures are:
Pa = Xa * Pa° (2)
Pb = Xb * Pb° (3)
Where Pa° and Pb° are the vapour pressures of each gases.
The mole fractions (Xa and Xb), can be expressed, one in function of the other:
Xa + Xb = 1 -----> Xa = 1 - Xb (4)
Now that we know this, we can replace (4) in (2), and then, (2) and (3) can be replaced in (1):
Pa = (1 - Xb)Pa°
P = (1 - Xb)Pa° + XbPb° (5)
Replacing the given data, we have:
263 = (1 - Xb)*425 + 151Xb
Now solving for Xb, which is the mole fraction of hexane:
263 = 425 - 425Xb + 151Xb
263 - 425 = (-425 + 151)Xb
-162 = -274Xb
Xb = -162 / -274
Xb = 0.59Hope this helps
what is a row of elements across the periodic table called
Answer:
a period
Explanation:
Answer: The row of elements across the periodic table is called "periods".
Explanation:
In the Periodic Table, there are seven rows of elements, which is called periods.
What amount of heat, in kJ, is required to vaporize 163.45 g of ethanol (C₂H₅OH)? (∆Hvap = 43.3 kJ/mol)
Answer:
Amount of heat required = 153.62 J
Explanation:
Given:
Mass = 163.45 g
∆Hvap = 43.3 kJ/mol
Molar mass C₂H₅OH = 46.07 g/mol
Find:
Amount of heat required
Computation:
Amount of heat required = Number of moles x Molar mass C₂H₅OH
Amount of heat required = [163.45/46.07][43.3]
Amount of heat required = 153.62 J
Calculate the bond energy in the ionic compound Nacl if the bond length is 2.36x10^-10m
This question is incomplete, the complete complete question is;
Coulomb's law for the energy of interaction between two charged ions;
E = Ke × q1q2/r
Coulomb's constant Ke = 2.31 × 10⁻²⁸ J.m.
Calculate the bond energy in the ionic compound NaCl if the bond length is 2.36 × 10⁻¹⁰m
Answer:
the bond energy is -9.788 × 10⁻¹⁹ J
Explanation:
Given the data in the question;
Ke = 2.31 × 10⁻²⁸ J.m which is the same as; Ke = 2.31 × 10⁻²⁸ Nm L/c²
ionic compound NaCl;
q1 = charge on Na in NaCl = Na⁺ = + 1C
q2 = charge on Cl in NaCl = Cl⁻ = - 1C
given that bond length r is 2.36 × 10⁻¹⁰m
E = Ke × q1q2/r
we substitute
E = 2.31 × 10⁻²⁸ × (+1 × -1) / 2.36 × 10⁻¹⁰
E = -2.31 × 10⁻²⁸ / 2.36 × 10⁻¹⁰
E = -9.788 × 10⁻¹⁹ J { The negative sign means Attraction in ions }
Therefore, the bond energy is -9.788 × 10⁻¹⁹ J
What observations did you make when the hydrochloric acid and zinc were combined?
Answer:
Zn + 2HCl -----> ZnCl2 + H2
Explanation:
Zinc chloride and hydrogen gas is formed
When zinc was combined with hydrochloric acid, hydrogen gas was evolved.
We know that a general property of metals is that they react with metals to evolve hydrogen gas. All metals that are above hydrogen in the activity series will undergo this reaction.
Hence, when hydrochloric acid and zinc were combined, the following reaction occured; Zn(s) + 2HCl(aq) -----> ZnCl2(aq) + H2(g). The colorless odorless gas evolved after this combination is hydrogen gas.
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Kate made some ice cubes from pure water.
She used a sensor to measure the temperature of the ice.
What temperature will the sensor show when the ice is melting?
............. °C
Answer:
The correct answer is - 0 degrees Celsius or 32 degrees Fahrenheit.
Explanation:
The pure water freezes below zero degrees Celsius and forms ice which is started to melt at zero degrees Celsius as it gets the heat from the surroundings. The change in the heat or temperature of matter leads to a change in the state of matter.
Kate will find that the ice cubes formed from the pure water started to melt at 0 degrees Celsius or 32 degrees Fahrenheit with the help of sensor she has.
An unknown solid is added to water in a calorimeter. The temperature of the water increases. What does this say about the reaction? A) The reaction is exothermic. B) The reaction is endothermic. C) The reaction has absorbed heat from the solution. D) The reaction has released heat to the solution. E) Both A and D are correct.
Answer:
Option A is correct.
Option D is correct.
E is the correct answer
Explanation:
This a theoretical calorimetry problem that can be solved by thermodynamic concepts.
Our system is the unknown solid. If the temperature of water has increased, we can think, that the heat from the metal was absorbed by water, which is our surrounding. If in the analysis of the situation we use a calorimeter, knowing that it is an isolated system, which does not allow the entry or exit of heat, we can conclude that the heat released is equal to the heat absorbed.
In conclusion, the thermodynamic system is constituted by the chemical reaction. In this case, the surrounding is made up of water and the calorimeter itself.
If the reaction is exothermic, the heat released by the reaction will be absorbed by the surrounding . Then, the final temperature will be higher than the initial temperature. If the reaction is endothermic, the heat absorbed by the reaction will be released by the environment. So, the final temperature will be lower than the initial temperature.Hydrocarbons are compounds that are composed of only carbon and hydrogen atoms. A hydrocarbon has a density of 2.59 g/L at STP. What is the molar mass of this hydrocarbon? Be sure to include units with your answer.
Answer:
58.0 g/mol
Explanation:
At STP, one mole occupies 22.4 liters. One mole of the hydrocarbon would have a mass of ...
(2.59 g/L)(22.4 L/mol) ≈ 58.0 g/mol
Answer:
58.0 g/molthe molar mass of this given hydrocarbonHow many molecules of glucose are in 1.15 mol of glucose, C6H1206?
Answer: There are [tex]6.926\times 10^{23}[/tex] molecules of glucose.
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the molecules, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadro's number}}[/tex]
[tex]1.15=\frac{x}{6.023\times 10^{23}}[/tex]
[tex]x=1.15\times 6.023\times 10^{23}=6.926\times 10^{23}[/tex]
Thus there are [tex]6.926\times 10^{23}[/tex] molecules of glucose.
The octane number of gasoline is a measure of octane activity. The octane activity is determined by comparing the engine performance using gasoline and known mixtures of isooctane and n-heptane.
a. True
b. False
Answer:
A. True
Explanation:
The octane number is determined by comparing the characteristics of gasoline to isooctane (2,2,4-trimethylpentane) and heptane. The correct option is option A.
Basically, the higher the octane number, the greater the resistance of the gasoline to knocking.
Which of the following chemical reactions is a single displacement reaction?
A. 2Na + O2→
Na2O
B. 2A1 + 3Zn(NO3)2 2AI(NO3)3 + 3Zn
C. Pb(NO3)2 + 2KBr → PbBr2 + 2KNO3
D. 2Fe(OH)3 Fe2O3 + 3H2O
Answer:
B. 2A1 + 3Zn(NO3)2 --> 2AI(NO3)3 + 3Zn
Explanation:
In the chemical equation, you can see that 2Al replaced 3Zn with (NO3)3 in the product, thus it is a single displacement reaction.
Answer:
B. 2A1 + 3Zn(NO3)2 --> 2AI(NO3)3 + 3Zn
Explanation:
One mole of a metallic oxide reacts with one mole of hydrogen to produce two moles of the pure metal
and one mole of water. 5.00 g of the metallic oxide produces 2.32 g of the metal. What is the metallic
oxide? (Use molar masses)
Answer:
Lithium oxide, Li₂O.
Explanation:
Hello!
In this case, according to the given amounts, it is possible to write down the chemical reaction as shown below:
[tex]M_2O+H_2\rightarrow 2M+H_2O[/tex]
Which means that the metallic oxide has the following formula: M₂O. Next, we can set up the following proportional factors according to the chemical reaction:
Thus, we perform the operations in order to obtain:
[tex]\frac{10X}{(2X+16)}=2.32[/tex]
So we solve for x as shown below:
[tex]10X=2.32(2X+16)\\\\10X=4.64X+37.12\\\\X=\frac{37.12}{10-4.64}\\\\X= 6.93g/mol[/tex]
Whose molar mass corresponds to lithium, and therefore, the metallic oxide is lithium oxide, Li₂O.
Best regards!