Answer:
This is because the half life of second order reactions is inversely proportional to the initial concentration of the reactant.
Explanation:
The equation to half life in the second order reactions is given by:
t1/2=1/[A]initial
From the equation, you can see that as the initial concentration of A increases the denominator also increases ,thus overall value (t1/2) decreases.
Hope this helps:)
The back of a water droplet acts as a mirror. When light hits the back of the water droplet, it bounces back to our eyes. This is called ____________.
Balance the following equation:
Cr + __02 +_Cr203
Answer:
4Cr + __302 -->_2Cr203.....
how many grams of caco3 are needed to react with 15.2g of hcl
Answer:
Balanced equation:
CaCO3 (s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l)
1mol CaCO3 will react with 2 mol HCl
Mol HCl in 32.8mL of 1.25M solution = 32.8mL / 1000mL/L * 1.25mol /L = 0.041 mol HCl
This will react with 0.041/2 = 0.0205 mol CaCO3
Molar mass CaCO3 = 100g/mol
Mass of CaCO3 reacted = 0.0205mol *100g/mol = 2.05g CaCO3.
Grams are the unit of weight or mass that depicts the quantity of a substance. The mass of calcium carbonate reacted is 2.05 gm.
What is mass?Mass is the product of the moles of the compound and its molar mass, it is given in grams.
The balanced chemical reaction is given as:
[tex]\rm CaCO_{3} (s) + 2HCl(aq) \rightarrow CaCl_{2}(aq) + CO_{2}(g) + H_{2}O(l)[/tex]
From the reaction, 1 mole of calcium carbonate reacts with 2 moles of hydrochloric acid.
Moles of hydrochloric acid is calculated as:
[tex]\begin{aligned} \rm n &= \rm Molarity \times Volume (L)\\\\&= 0.0328 \times 1.25\\\\&= 0.041\;\rm mol\end{aligned}[/tex]
Now, the moles of calcium carbonate it will react with will be 0.0205 moles.
Mass of calcium carbonate is calculated as:
[tex]\begin{aligned} \rm mass &= \rm molar\; mass \times moles\\\\&= 0.0205 \times 100\\\\&= 2.05 \; \rm g\end{aligned}[/tex]
Therefore, 2.05 gm of calcium carbonate is needed to react with 15.2 gm of hydrochloric acid.
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A rigid container of O2 has a pressure of 2551 mmHg at a temperature of 713 K. What is the pressure at 273 K?
Answer:977.34
Explanation:
divide 2551 and 273 to get 3.778. then multiply 3.78 by 273 to gry 977.34.
A trophic level is a number that tells you the position an organism occupies in a food chain or food pyramid.
True
False
Answer:
true
Explanation:
Choose the options below that are true of standard reduction potential. (select all that apply) Select all that apply: All standard reduction potentials are measured against that of the reduction of hydrogen ions to H2 gas. The standard reduction potential of a cell is determined by subtracting the standard reduction for the reaction at the anode from the standard reduction potential for the reaction at the cathode. Standard reduction potentials are dependent on reaction stoichiometry. The standard reduction potential for a cell is determined by adding the standard reduction potential for the reaction at the anode to the standard reduction potential for the reaction at the cathode.
Answer:
All standard reduction potentials are measured against that of the reduction of hydrogen ions to H2 gas.
Explanation:
The standard hydrogen electrode (SHE) serves as a sort of reference electrode. All standard electrode potentials of chemical systems are measured against the standard hydrogen electrode whose electrode potential has been arbitrarily set at 0.00 V.
The reduction potential of any other system is measured against the standard hydrogen electrode by connecting that half cell to the standard hydrogen electrode and observing the reading of the voltmeter. The standard hydrogen electrode consists of hydrogen ions of unit activity, hydrogen gas at 1 atm and the system is maintained at a temperature of 298 K.
Standard reduction potentials are measured against that of the reduction of hydrogen ions to [tex]H_2[/tex] gas because hydrogen is chosen as a standard reference and has electrode potential zero.
It is impossible to measure absolute electrode potential for an electrode without forming cell . Therefore it is assumed that standard electrode potential for hydrogen is zero
The standard reduction potential of a cell is determined by subtracting the standard reduction for the reaction at the anode from the standard reduction potential for the reaction at the cathode.
[tex]E_c_e_l_l[/tex]°[tex]= E_c_a_t_h_o_d_e[/tex]°[tex]- E_a_n_o_d_e[/tex]°
The species liking to get reduced is defined in term of standard reduction potential.
The species whose standard reduction potential is to be calculated is placed at cathode and at anode hydrogen electrode is used.
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PLEASE HELP!
The specific heat of octane, C8H18(l), is 2.22 J/(g⋅K).
How much heat is needed to raise the temperature of 76.0 g of octane from 10.6 ∘C to 26.0 ∘C?
Express your answer in joules to three significant figures.
Answer:
Q = 2.60 • [tex]10^{3}[/tex] J
Explanation:
Our specific heat capacity equation is:
Q = mC∆T
Q is the energy in joules.
m is the mass of the substance.
∆T is the temperature chance.
Let's plug in what we know.
We have 76.0 g of octaneThe specific heat capacity of octane is 2.22 J/(g•K)The temperature increases from 10.6º to 26.0º (a 15.4º increase)Q = 76.0(2.22)(15.4)
Multiply.
Q = 2598.288
We want three significant figures.
Q = 2.60 • [tex]10^{3}[/tex]
or
Q = 2590 J
Hope this helps!
Answer:6,985.008
Explanation:
so the hear formula is mass times specific heat times change in temperature (kelvin) so what i did was got the change in temperature (41.4 K) and multiplied that times 2.22 J/(g•K)and multiplied that by 76 grams of Octane to get the Answer (not in scientific notation)
True or False
a. The cones in our eyes detect color, while the rods perceive brightness.
b. In white light, white objects absorb all the colors.
c. At night, when light is dim, our cones are not activated so objects will appear as their normal color.
P.
d. Violet has the longest wavelength which is why it gets refracted the most.
V
e. The angle of incidence always equals the angle of reflection.
true
false
true
true
false
How many formula units are there in 14.50 moles of any compound?
___X 10^___formula units
Answer:
8.73 × 10²⁴ formula units
Explanation:
To calculate the number of formula units a substance contain, we multiply the number of moles by Avagadro number (6.02 × 10²³)
number of formula units = 14.50 moles × 6.02 × 10²³
= 87.29 × 10²³
= 8.73 × 10²⁴ formula units.
A gas has an initial pressure of 120 kPa, a volume of 23 liters, and a temperature of 20°C. If the pressure is raised to 150 kPa the new volume is 17 liters, what is the new temperature of the gas? *
A.100 K
B.0.003 K
C.270.7 K
D.18.4 K
Where and why the U.S. acid rain damage is the greatest.
Answer:
Some acid rain occurs naturally, but sulfur dioxide and nitrogen oxide emissions from smokestacks combine with rain to make sulfuric and nitric acid in amounts that harm.
Explanation:
Which of the following are acid formulas? (Choose 2)
NH3
CH3OH
NaOH
HNO3
H2SO4
CH4
Answer:
HNO3 & H2SO4
Explanation:
HNO3 is Nitric acid and H2SO4 is Sulphuric acid
Teresa has taken three tests worth 100 points each. Her scores are 85, 93, and 88. She has one test left to take.
To get an average score of 90, what must the sum of all her test scores be?
a.
400
c.
600
b.
360
d.
300
Answer:
SOrry it makes me writer sotufjksankdn
Explanation:
HELP!! Suppose that the pressure of 1.00 L of gas is 380 mm Hg when the temperature is 200. K. At what
temperature is the volume 2.00 L and the pressure 0.750 atm?
why metal in the middle of metal activity series can't be obtained by heating ors in air
Answer:
See Explanation
Explanation:
The way by which a metal is obtained from its ore is determined by the chemical reactivity of the metal.
Metals that are highly reactive are chiefly obtained by electrolysis of the metal salt. These metals are found high up in the metal activity series.
Metals that are at the middle of the series are moderately reactive and are obtained by electrolysis or by reduction since they still form ionic salts.
Metals that are far lower in the series can only be obtained by heating them in air because they are mostly unreactive.
Hence, moderately reactive metals at the middle of the series are not obtained by roasting in air.
If you have 0.30 moles of gas that has a volume of 7.5 L, how many moles of gas will you need to have a volume of 30.0 L?
Answer:
[tex]187.[/tex]
Explanation:
[tex]7.5 \div 0.30 = 25[/tex]
[tex]7.5 \times 25 = 187.5[/tex]
I’d appreciate the help! :)
Here is the reaction:
3 NO2 (g) + H2O (l) = 2HNO3 (l) + NO (g)
Answer: 300g
Explanation:
first we write the given values on top
224L. x
3 NO2 (g) + H2O (l) = 2HNO3 (l) + NO (g)
22.4L 30g
then we form a formula
224L/22.4L= x/30g
224*30/22.4
6720/22.4= 300g
A 10 M concentrated stock solution of NaCl is used to prepare 2 liters of diluted 1 M
solution. Which of the following is true for the process used to achieve the required
dilution? (5 points)
O The volume of the solvent used is less than 0.1 liters.
O The volume of stock solution used is less than 0.1 liters.
The volume of stock solution used is more than 2 liters.
The volume of the solvent used is less than 2 liters.
Answer: It is true for the process used to achieve the required dilution that volume of the solvent used is less than 2 liters.
Explanation:
Given: [tex]M_{1}[/tex] = 10 M, [tex]V_{1}[/tex] = ?
[tex]M_{2}[/tex] = 1 M, [tex]V_{2}[/tex] = 2 L
The volume of stock solution is calculated as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\10 M \times V_{1} = 1 M \times 2\\V_{1} = 0.2 L[/tex]
A solution which contains small amount of solute is called a dilute solution. Whereas a solution which contains more amount of solute is called a concentrated solution.
The stock solution is used for dilution and hence, it acts as a solvent. Its calculated volume is 0.2 L.
This means that volume of the solvent used is less than 2 liters.
Thus, we can conclude that it is true for the process used to achieve the required dilution that volume of the solvent used is less than 2 liters.
Answer: The volume of the solvent used is less than 2 liters.
Explanation:
112 g of aluminum carbide react with 174 g water to produce methane and aluminum hydroxide in the reaction shown below.
2 Al4C3(s) + 12 H2O(l) → 3 CH4(g) + 4 Al(OH)3(s)
If aluminum carbide is the limiting reactant, how many moles of the excess reactant are left over
a
37.3 mol
b
4.68 mol
c
7.33 mol
d
131.94 mol
Answer: 4.999 moles of excess reactant will be left over.
Explanation:
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
Given mass of aluminium carbide = 112 g
Molar mass of aluminium carbide = 143.96 g/mol
Putting values in equation 1:
[tex]\text{Moles of aluminium carbide}=\frac{112g}{143.96g/mol}=0.778mol[/tex]
For the given chemical reaction:
[tex]2Al_4C_3(s)+12H_2O(l)\rightarrow 3CH_4(g)+4Al(OH)_3(s)[/tex]
By the stoichiometry of the reaction:
2 moles of aluminium carbide reacts with 12 moles of water
So, 0.778 moles of aluminium carbide will react with = [tex]\frac{12}{2}\times 0.778=4.668 mol[/tex] of water
Given mass of water = 174 g
Molar mass of water = 18 g/mol
Putting values in equation 1:
[tex]\text{Moles of water}=\frac{174g}{18g/mol}=9.667mol[/tex]
Moles of excess reactant (water) left = 9.667 - 4.668 = 4.999 moles
Hence, 4.999 moles of excess reactant will be left over.
Balancing equations helps please !!
Explanation:
3. 2AlBr3 + 3k2SO4----------> 6KBr + Al2(SO4)3
stay safe healthy and happy.I am one percent away from failing. I just need help. No false answers
How many grams of Al(OH)3 are produced from 3.00 g of AlCl3 with excess of NaOH?
Answer:
I did it in steps in the picture I just hope it helps you to understand:)
WHAT DO THESE DIAGRAMS MEAN PLS HELP
Answer:
(I). Evaporation
(ii). Sublimation
Gas particles that are at low temperature and high pressure and are close to changing phases are considered:
a)Real Gases
b)Ideal Gases
c)Both Ideal and Real Gases
Help please ! ASAP neeeeeed and answerrrrrr
Answer:
The answer is D
Explanation:
Answer:
A. Heater will only become warm when switch is closed.
Explanation:
Switches are used to control the flow of electrons (basically electricity). If you look at the other trials, you see that when switch is open, the bulb or fan does not run cuz no electricity can get to them. But when switch is closed, electricity gets to them. Thus, they will experience similar thing with the heater I assume cuz they have not said anything about battery voltage or anything preventing heater from heating.
Alkenes are more stable than alkanes. True or False
Answer:
Yes
Explanation:
Alkenes are relatively stable compounds, but are more reactive than alkanes because of the reactivity of the carbon–carbon π-bond. Most reactions of alkenes involve additions to this π bond, forming new single bonds.
Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. What is the balanced equation for this reaction?
○C5H12(g) + O29) - CO2(g) + H2O(g) ○C5H12(g) + O2(g) - 5CO2(g) + H2O(g)
○C5H12(g) +802(g) - 5CO2(g) + 6H2O(g) ○5CO2(g) + 6H2009) - C5H12(g) + 802(g)
○C5H12(g) +502(g) - 5CO2(g) + 6H2(g)
○CH2(g) +O2(g) + CO2(g) + H2(g)
Answer:
C
Explanation:
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g)
The balanced chemical equation of pentane (C5H12) which reacts with oxygen is
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g)
What is balanced chemical equation?It is the chemical equation in which the atom or molecules or moles of elements on both side reactant and product.
Our reactants are pentane and oxygen. Since, fourth and sixth reaction do not contain pentane. Therefore, fourth and sixth reaction are wrong.
Now, our next step is to compare product.
As we know that, Carbon dioxide and water are produced when pentane (C5H12) reacts with oxygen. So, we get to the conclusion that carbon dioxide and water are the product.
Since, rest of the equation have carbon dioxide and water as product.
On reactant side, there are 5 carbon atoms and 12 hydrogen atom. So, on product side there must be 5 carbon atoms and 12 hydrogen atom. Now we balance the oxygen atom on both side.
Thus, we concluded that the balanced chemical equation of pentane (C5H12) which reacts with oxygen is
C5H12(g) +802(g) - 5CO2(g) + 6H2O(g).
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PLEASE QUICKLY. I'll give BRAINLIEST. A sample contains 25% parent isotope and 75% daughter isotopes. If the half-life of the parent isotope is 72 years, how old is the sample?
144 years old
216 years old
288 years old
360 years old
From the calculations and the principles of radioactivity, the age of the parent isotope is 144 years
What is radioactivity?The term radioactivity has to do with the spontaneous decay of a substance.
We know that we have about 25% parent isotope still remaining hence;
[tex]0.693/t1/2 =2.303/t log No/N\\When N =0.25 No and t1/2 = 72 years\\0.693/72 =2.303/t log No/0.25No\\0.0096 = 2.303/t *0.60206\\0.0096 = 1.3865/t\\t = 1.3865/0.0096\\t =144 years[/tex]
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Answer:
A. 144 years old
Explanation:
What is the mass of a sample of NH3 containing 3.80 x 1024 molecules of NH3? (5 points)
74.8 grams
107 grams
89.4 grams
101 grams
Answer: 107 grams
Explanation: got it right on the test
The mass of a sample of f NH₃ containing 3.80 x 10²⁴ molecules of NH₃ is 107.27 grams.
What is a molecule?A molecule is a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance.
6.02214076 × 10²³ molecules constitute 1 mole of NH₃
3.80 x 10²⁴ molecules constitutes of = 6.31 moles
1 mole of NH₃ = 17 gm
11.19 mole will be = 17 X 6.31
= 107.27 grams
Therefore the mass of a sample of NH₃ containing 3.80 x 10²⁴ molecules of NH₃ is 107.27 grams.
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Which will decrease the rate of a reaction?
changing the temperature from 90ºC to 40ºC
adjusting the concentration from 30 ng to 60 ng
placing the substance in a smaller container
grinding the substance into a powder
Explanation:
The reaction rate decreases with a decrease in temperature. Catalysts can lower the activation energy and increase the reaction rate without being consumed in the reaction. Differences in the inherent structures of reactants can lead to differences in reaction rates.
What is the main purpose of phloem tissue?
to carry food from the leaves to all the cells of the plant
to absorb water and minerals from the soil
to store extra food for the plant to use in the winter
to carry water and minerals from the roots to the lea