Answer:
sorry don't know the answer!!!
Calculate the number of hydrogen atoms present in 40g of urea, (NH2)2CO
Answer: There are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms.
So, the number of atoms present in 0.67 moles are as follows.
[tex]0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms[/tex]
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
[tex]4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms[/tex]
Thus, we can conclude that there are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
The mass of 1.63×10^21 silicon atoms
Answer:
I think it is 7.60 X 1
but if it's not srry
A 1.0 kg bottle of sodium carbonate (Na2CO3, 106.0 g/mol) is available to clean up 5.00 liters of spilled concentrated aqueous hydrochloric acid (9.75 M). Is this enough sodium carbonate to neutralize the acid according to the following reaction?
2 HCl (aq) + Na2CO3 (s) 2NaCl (aq) + CO2 (g) + H2O (l)
(1) No, there is approximately 40% too small amount of sodium carbonate needed.
(2) Yes, there is approximately 80% more than what is needed.
(3) No, there is approximately 60% too small amount of sodium carbonate needed.
(4) Yes, there is exactly enough sodium carbonate, but no excess.
(5) No, there is approximately 20% too small amount of sodium carbonate needed.
Answer:
The correct answer is option 4, that is, there is exactly enough sodium carbonate.
Explanation:
Based on the given question, the reaction will be,
2 HCl (aq) + Na2CO3 (s) ⇒ 2 NaCl (aq) + CO2 (g) + H2O (l)
Therefore, for neutralizing 2 moles of HCl, one mole of Na2CO3 is required.
No of moles present in 1 Kg or 1000 grams of Na2CO3 will be,
Moles = Weight/Molecular mass of Na2CO3
Moles = 1000 / 106 = 9.43
Thus, 9.43 moles of Na2CO3 is present.
No of moles present in 1 liter of 9.75 M HCl is 9.75.
No. of moles present in 5 Liters of HCl (9.75 M),
= 5 × 9.75 = 48.75
Thus, for 2 moles of HCl 1 mole of Na2CO3 is required. Now for 48.75 moles of HCl, the moles required of Na2CO3 is 9.75. Therefore, for complete neutralization, the moles of Na2CO3 required is 9.75, and the present moles is 9.43.
Hence, there is exactly enough sodium carbonate.
Which waves are blocked by the atmosphere? A. gamma rays B. visible light C. radio waves D. infrared waves
Answer: look at the explanation and try to work it
Explanation: in contrast, our atmosphere blocks most ultraviolet light (UV) and all X-rays and gamma-rays from reaching the surface of Earth. Because of this, astronomers can only study these kinds of light using detectors mounted on weather balloons, in rockets, or in Earth-orbiting satellites.
Calculate the mass of 100.0 mL of a substance whose density is 19.32 kg/L. Express your answer in kilograms using the correct number of significant figures. Do not enter your answer using scientific notation.
Answer:
1.932 kg
Explanation:
First we convert 100.0 mL to L:
100.0 mL / 1000 = 0.1000 LThen we calculate the mass of the substance, using the definition of density:
Density = mass / volumemass = density * volume19.32 kg/L * 0.1000 L = 1.932 kgAs the multiplication involves two numbers of 4 significant figures each, the answer needs to have 4 significants figures as well.
PLEASE HELP ME!!!!
TRUE or FALSE: When sperm and egg cells combine in fertilization, the
offspring ends up with the same number of chromosomes as their
parents.
Answer: False
Explanation:
Hope this help
Answer:
True.
Explanation:
Every child will contain the same number of chromosomes as the parents (otherwise they wouldn't be considered the same species). Additionally, animals can only mate with a species containing the same number of chromosomes as themselves. This means if the offspring of the parents had a different number fo chromosomes the offspring would be unable to mate with animals of it's own species.
A chemist must dilute of aqueous silver perchlorate solution until the concentration falls to . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to significant digits
The given question is incomplete, the complete question is:
A chemist must dilute 54.1 mL of 20.2 M aqueous silver perchlorate (AgC102) solution until the concentration falls to 3.00 M. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to 3 significant digits.
Answer:
The correct answer is 0.364 L.
Explanation:
A solution is made less concentrated by diluting it with a solvent. There is no change in the number of moles when more solvent is added to the solution. In case, if the solution is diluted from V1 to V2, a change is noticed in the molarity of the solution based on the given equation,
M1V1 = M2V2
In the given case, the V1 or the volume of the original solution is 54.1 ml, M1 or the molarity of the original solution is 20.2 M.
The M2 or the molarity of the diluted solution is 3.00 M, there is a need to find the V2 or the volume of the diluted solution.
Now by putting the values in the equation we get,
= 20.2M * 54.1 ml = 3.0 M * V2
V2 = 364.27 ml
It is known that 1000 ml is equivalent to 1L, therefore, 1 ml = 0.001 L
Now, the value of V2 will be,
= 364.27 * 0.001 L = 0.36427 L or 0.364 L
how many moles of Carbon are in 3.06 g of Carbon
Answer:
[tex]\boxed {\boxed {\sf 0.255 \ mol \ C }}[/tex]
Explanation:
If we want to convert from grams to moles, the molar mass is used. This is the mass of 1 mole. They are found on the Periodic Table as the atomic masses, but the units are grams per mole (g/mol) instead of atomic mass units (amu).
Look up the molar mass of carbon.
Carbon (C): 12.011 g/molSet up a ratio using the molar mass.
[tex]\frac {12.011 \ g \ C}{ 1 \ mol \ C}[/tex]
Since we are converting 3.06 grams to moles, we multiply by that value.
[tex]3.06 \ g \ C*\frac {12.011 \ g \ C}{ 1 \ mol \ C}[/tex]
Flip the ratio. This way, the ratio is still equivalent, but the units of grams of carbon cancel.
[tex]3.06 \ g \ C* \frac{1 \ mol \ C}{12.011 \ g\ C}[/tex]
[tex]3.06 * \frac{1 \ mol \ C}{12.011 }[/tex]
[tex]\frac {3.06}{12.011 } \ mol \ C[/tex]
[tex]0.25476646 \ mol \ C[/tex]
The original measurement of grams (3.06) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place.
0.25476646The 7 in the ten-thousandth place tells us to round the 4 up to a 5.
[tex]0.255 \ mol \ C[/tex]
3.06 grams of carbon is approximately 0.255 moles of carbon.
A 50.00 g sample of a compound containing only carbon, hydrogen, and oxygen was partially analyzed. The sample contained 24.66 g carbon, and 3.43g of hydrogen. The molecular weight of the compound was determined to be 146.0 amu. Determine emperical the molecular formula of the compound
Answer:
1. Empirical formula => C₂H₃O
2. Molecular formula => C₆H₉O₃
Explanation:
From the question given above, the following data were obtained:
Mass of compound = 50 g
Mass of Carbon = 24.66 g
Mass of Hydrogen = 3.43 g
Molecular weight of compound = 146.0 amu
Empirical formula =?
Molecular formula =?
Next, we shall determine the mass of oxygen in the compound. This can be obtained as follow:
Mass of compound = 50 g
Mass of C = 24.66 g
Mass of H = 3.43 g
Mass of O =?
Mass of O = mass of compound – ( mass of C + mass of H)
= 50 – (24.66 + 3.43)
= 50 – 28.09
= 21.91 g
1. Determination of the empirical formula.
Mass of C = 24.66 g
Mass of H = 3.43 g
Mass of O = 21.91 g
Divide by their molar mass
C = 24.66 / 12 = 2.055
H = 3.43 / 1 = 3.43
O = 21.91 / 16 = 1.369
Divide by the smallest
C = 2.055 / 1.369 = 2
H = 3.43 / 1.369 = 3
O = 1.369 / 1.369 = 1
Therefore, the empirical formula of the compound is C₂H₃O
2. Determination of the molecular formula.
Molecular weight of compound = 146.0 amu
Empirical formula => C₂H₃O
Molecular formula =?
Molecular formula = [C₂H₃O]ₙ = molecular weight
Thus,
[C₂H₃O]ₙ = 146
[(12×2) + (3×1) + 16]n = 146
[24 + 3 + 16]n = 146
43n = 146
Divide both side by 43
n = 146 / 43
n = 3
Molecular formula = [C₂H₃O]ₙ
Molecular formula = [C₂H₃O]₃
Molecular formula = C₆H₉O₃
If in Part II, you mixed (carefully measured) 25.0 mL of 0.81 M NaOH with 65.0 mL of 0.33 M HCl, which of the two reagents is the limiting reagent for heat of reaction
Answer:
NaOH is the limiting reactant.
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary to write out the chemical reaction between NaOH and HCl:
[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]
Thus, since they react in a 1:1 mole ratio; we can now calculate the moles of each substance by using their volumes and molarities:
[tex]n_{NaOH}=0.0250L*0.81mol/L=0.02025molNaOH\\\\n_{HCl}=0.0650L*0.33mol/L=0.02145molHCl[/tex]
Now, since NaOH is in a fewer proportion, we infer just 0.02025 moles of HCl are consumed so that 0.0012 moles of this acid remain unreacted; in such a way, we infer that the NaOH is the limiting reactant for this reaction.
Regards!
If a gas is at a pressure of 46 mm Hg and temperature of 640 K, what would be the temperature if the pressure was raised to 760 mm Hg?
Answer:
10573.9K
Explanation:
Using pressure law equation;
P1/T1 = P2/T2
Where;
P1 = initial pressure (mmHg)
P2 = final pressure (mmHg)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information provided in this question,
P1 = 46mmHg
P2 = 760mmHg
T1 = 640K
T2 = ?
Using P1/T1 = P2/T2
46/640 = 760/T2
Cross multiply
640 × 760 = 46 × T2
486400 = 46T2
T2 = 486400 ÷ 46
T2 = 10573.9K
Map
Formulate your hypothesis.
List down the materials.
• Write the methods.
Answer:
How to Formulate an Effective Research Hypothesis
State the problem that you are trying to solve. Make sure that the hypothesis clearly defines the topic and the focus of the experiment.
Try to write the hypothesis as an if-then statement. ...
Define the variables.
Explanation:
The table below shows some characteristics of three different types of muscles
Answer: Type A are cardiac muscles Type B are skeletal muscles, and Type C are smooth muscles.
Explanation: sub to technoblade :P
Water moves on, above or under the surface of the Earth true or false
above because its above
If the specific heat capacity of copper is 387 J/kg/°C, then how much energy is needed to raise the temperature of 400 g of copper from 30°C to 55°C?
Answer:
Explanation:
mass = 400 grams * [1 kg/1000 grams] = 0.400 kg
c = 387 Joules / (oC * kg)
Δt = 55 - 30 = 25 oC
E = m*c * Δt
E = 0.4 * 387 * 25
E = 3870 Joules
In the following reaction, C5H12(1) + 8 O2 (g) - 6 H2O (g) + 5 CO2 (g), how many
moles of water (H20) are produced by 14.2 moles of O2?
Answer:
10.65 moles
Explanation:
O2:H2O
8:6
14.2:x
x= 10.65 moles
PLEASE HELP ME!!!!!!!
Answer:
The heat capacity of the metal underneath the gold is 0.431 J/g°C
Explanation:
Using the formula as outlined in the image:
Q = m × c × ∆T
Where;
Q = amount of heat energy (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the information in this question;
Q = 503.9J
m = 23.02g
c = ?
∆T = 74°C - 23.2°C = 50.8°C
Using Q = m × c × ∆T
c = Q ÷ m∆T
c = 503.9 ÷ (23.02 × 50.8)
c = 503.9 ÷ 1169.42
c = 0.431 J/g°C
From the above heat capacity of the metal underneath the gold, it is obvious that the metal is not pure gold (c = 0.129J/g°C)
When water and alcohol are mixed, the final volume is less than the total of volume of alcohol plus water added due to .......
Answer:
molecules take up more space
PbO2 + 4HCl --- PbCl2 + Cl2 + 2H2O who buys electrons and who loses electrons?
Answer: Electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is also called the reaction where the exchange of electrons takes place.
An oxidation reaction is defined as the reaction in which a chemical species loses electrons takes place. In this reaction, the oxidation state of a substance gets increased.
A reduction reaction is defined as the reaction in which a chemical species gains electrons takes place. In this reaction, the oxidation state of a substance gets reduced.
For the given chemical reaction:
[tex]PbO_2+4HCl\rightarrow PbCl_2+Cl_2+2H_2O[/tex]
The half-reactions for this redox rection follows:
Oxidation half-reaction: [tex]2HCl\rightarrow ClO_2 + 2e^-[/tex]
Reduction half-reaction: [tex]PbO_2+2e^-\rightarrow PbCl_2[/tex]
Hence, electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]
Which of these is an ion with a charge of 1+?
scenario Juan and Maria Lopez wish to invest in a no-risk savings account. They currently have 530,000 in an account bearing 5.25 % annual interest, compounded continuously. The following options are available to them.
Answer:
The amount after three year is 617934.1302
Explanation:
Complete question
A person places $530,000 in an investment account earning an annual rate of 5.25%, compounded continuously. Using the formula V = Pe^{rt}V=Pe rt , where V is the value of the account in t years, P is the principal initially invested, e is the base of a natural logarithm, and r is the rate of interest, determine the amount of money, to the nearest cent, in the account after 3 years
Solution
The formula for calculating compound interest is
[tex]A = p (1 + \frac{r}{n})^{nt}[/tex]
Substituting the given values we get -
[tex]A = 530,000 (1 + \frac{5.25}{100})^3\\A = 530,000 * ( 1+ 0.0525)^3\\A = 530,000 * ( 1.0525)^3\\A = 617934.1302[/tex]
The amount after three year is 617934.1302
NEED HELP ASAP!!!.....Which is not true about the ionic compound sodium chloride (NaCl)? A.)it was formed when electrons were shared B.)it is electrically neutral C.)it has properties different from the atoms from which it is formed D.)it is a white crystalline solid
1. What happens when like charges are brought closer to each other?
Congratulations you have worked hard and now you are done with the year! I am so proud of you!
Answer:
lololol
Explanation:
I need help with my chemistry but you can only choose one correct answer
Answer:
Explanation:
photosynthesis
the given chemical reaction is photosynthesis.
During photosynthesis carbon dioxide absorbed by plants reacts with water in presence of sunlight to give glucose and oxygen.
The solubility of an ionic compound can be expressed as the number of moles of the compound that will dissolve per liter of solution (molarity). The saturated solution has approximately____(a) sodium ions dissolved in it (give an estimate of the average value.) The solution (not the solid) contains approximately_____(b) moles of sodium ions.
Answer:
Number of moles of sodium dissolved = 6.0 *10^23
Explanation:
The image for the question is attached
Solution
a) Total 181 ions of Na are dissolved
b)
The number of moles of sodium dissolved = 181/6.023 *10^23
Number of moles of sodium dissolved = 5.987 * 10^23
Number of moles of sodium dissolved = 6.0 *10^23
Which element has the smallest mass on the periodic table? *
O
H
Pb
He
Mg
Answer:
That should be Hydrogen.
So The second option Is legit!
Determine the molarity and mole fraction of a 1.09 m solution of acetone (CH3COCH3) dissolved in ethanol (C2H5OH). (Density of acetone
Answer:
Molarity = 0.809 M
mole fraction = 0.047
Explanation:
The complete question is
Calculate the molarity and mole fraction of acetone in a 1.09-molal solution of acetone (CH3COCH3) in ethanol (C2H5OH). (Density of acetone = 0.788 g/cm3; density of ethanol = 0.789 g/cm3.) Assume that the volumes of acetone and ethanol add.
Solution -
Solution for molarity:
1.09-molal means 1.09 moles of acetone in 1.00 kilogram of ethanol.
1)
Mass of 1.09 mole of acetone
= 1.09 mol x 58.0794 g/mol = 63.306 g
Density of acetone = 0.788 g/cm3
Thus, volume of 1.09 moles of acetone = 63.306 g/0.788 g/cm3 = 80.34 cm3
For ethanol
1000 g divided by 0.789 g/cm3 = 1267.427 cm3
Total volume of the solution = Volume of acetone + Volume of ethanol = 80.34 cm3 + 1267.427 cm3 = 1347.765 cm3 = 1.347 L
a) Molarity:
1.09 mol / 1.347 L = 0.809 M
Mole Fraction
a) moles of ethanol:
1000 g / 46.0684 g/mol = 21.71 mol
b) moles of acetone:
1.09 / (1.09 + 21.71) = 0.047
what is a compound ? Give five examples ?
[tex]\huge\mathsf{\red{\underline{\underline{Compound}}}}[/tex]
[tex]{\green{\dashrightarrow}}[/tex]A chemical compound is a chemical substance that is made of two or more atoms of different elements that share a chemical bond.
[tex]{\green{\dashrightarrow}}[/tex]A chemical formula represents the ratio of atoms per element that make up the chemical compound.
[tex]\large{\pink{\sf{5~ Examples~ of~ Compound~ are:-}}}[/tex]
Example 1 :-Water (H2O, consisting of 2 hydrogen atoms and one oxygen atom)Example 2 :- Carbon dioxide (CO2, consisting of one carbon atom and two oxygen atoms)Example 3 :- Sodium Chloride (NaCl, consisting of one sodium atom and one chloride atom)Example 4:-Methane (CH4, consisting of one carbon atom and four hydrogen atoms)Example 5 :- Pure glucose is a compound made from three elements - carbon, hydrogen, and oxygen. The ratio of hydrogen to carbon and oxygen in glucose is always 2:1:1.
ins1502 assignment 03
Answer:
I think you forgot to post the question or picture