Molecular Mass

Q.

How do I get the molar mass of urea?

Q.

Find the mass ratio of carbon to oxygen in carbon dioxide?

1. 3:8

2. 8:3

3. 1:8

4. 4:1

Q.

Calculate The Molecular Mass Of The Following:

(A) ${\mathrm{H}}_2{\mathrm{CO}}_3$

(B) ${\text{C}}_2{\mathrm{H}}_5\mathrm{OH}$

(C) ${\mathrm{H}}_2{\mathrm{SO}}_4$

Q.

What is the relative molecular mass of cane sugar?

1. 342

2. 240

3. 345

4. 350

Q.

Calculate the mass per cent composition of copper in copper sulfate.(Cu=64, S=32, O=16)​

Q.

A hydride of nitrogen contains $87.5$ percent by mass of nitrogen. Determine the empirical formula of this compound.

Q. Molecular mass of sulphuric acid (${\text{H}}_2\text{S}{\text{O}}_4$ ) is 132u.

1. True
2. False

Q.

$Mass\%$ of oxygen in Glucose is _____

1. 

2. 

3. 

4. 

Q.

What is the percentage composition of Water in Gypsum salt?

1. 20.93%
2. 23.60%
3. 21.93%
4. 22.52%

Q.

Which of the following statements is/are correct for 80 g of oxygen?

1. Statement (i) is correct.

2. Statement (ii) is correct.

3. Statement (iii) is correct.

4. Statement (iv) is correct.

Q.

For the chemical equation given below, what is the amount of methane required to produce 72 g of water?
$C{H}_4\left(g\right)+2O_2\left(g\right)\to C{O}_2\left(g\right)+2H_{2}O\left(l\right)$

1. 32 g

2. 44 g

3. 64 g

4. 16 g

Q.

Caffeine has a molecular weight of $194$. If it contains $28.9\%$ by mass of nitrogen, the number of atoms of nitrogen in one molecule of caffeine is:

1. 2

2. 3

3. 4

4. 6

Q.

An astronaut makes water on the moon by mixing hydrogen and oxygen. Will the mass ratio of hydrogen to oxygen of the water that he made on the Moon will be same as that on the Earth?

1. On moon the water will have lighter mass than on earth.

2. On moon the water will have heavier mass than on earth

3. It will be different.

4. It will be the same.

Q. An organic compound on analysis gave the following percentage composition : C = 57.8%, H = 3.6% and the rest is oxygen. The vapour density of the compound was found to be 83. Find out the molecular formula of the compound.

Q. What will be the increase in mass of magnesium, if 120g of magnesium is heated in presence of oxygen?

Q.

The molecular mass of Na₂CO₃ is:

1. 102 g

2. 104 g

3. 106g

4. 108 g

Q. Calculate the molecular mass of the following:
$(N{H}_4{)}_{2}C{O}_3$

Q.

Choose the option(s) that show correct molecular masses of mentioned molecules:-

1. $H_{2}O$ = 18u

   $C{O}_2$ = 40u

2. $C{O}_2$ = 44u

   $H_{2}S{O}_4$ = 98u

3. $HCl$ = 36.5u

   $H_{2}S{O}_4$ = 96u

4. $S{O}_2$ = 64u

   $HCl$ = 36.5u

Q.

The mass ratio of carbon to hydrogen in methane is 3:1. How much amount of hydrogen is required to react with 36 gms of carbon to form methane?

1. 10 g

2. 12 g

3. 16 g

4. 30 g

Q.

Define the mass number of an element.

Q. A mixture of $1.65\times {10}^{21}$ molecules of X and $1.85\times {10}^{21}$ molecules of Y weighs 0.688 g. If molecular mass of Y is 187, what is the molecular mass of X?

1. $41.35$
2. $41.65$
3. $42.35$
4. $41.75$

Q.

Find the mass of $1.2044\times {10}^{23}$ molecules of limewater.

1. 5.7 g

2. 148 g

3. 57 g

4. 14.8 g

Q.

What is the relative molecular mass of $CuS{O}_4.5H_{2}O$? Given the mass of $Cu=63.5amu$

1. 177.5 amu

2. 249.5 amu

3. 342.0 amu

4. 877.5 amu

Q. The molecular mass of $CuS{O}_4.5H_{2}O$ is:

1. 233.5 gm/mole
2. 249.5 gm/mole
3. 251.5 gm/mole
4. 247.5 gm/mole

Q.

What is the mass of 4.82 x ${10}^{25}$ molecules of $H_{2}O$ in grams?

___

Q. Define the following terms:
(i) Atomic mass
(ii) Molecular mass
(iii) Formula mass

Q.

What is the percentage composition of water in Gypsum salt?

1. 21 %

2. 30 %

3. 19 %

4. 25 %

Q. Match the molecules present in set 1 with their molecular mass present in set 2.

Set 1	Set 2
a) Oxygen molecule	(i) 44
b) Carbon dioxide	(ii) 18
c) Water	(iii) 32

1. a-(iii), b-(i), c-(ii)
2. a-(ii), b-(i), c-(iii)
3. a-(iii), b-(ii), c-(i)
4. a-(i), b-(iii), c-(ii)

Q.

A patient Vasu had to survive for a month on artificial respiration before he passed away. A nurse was instructed to give him 7.5g of glucose per hour for consumption to meet the energy requirement. What volume of carbogen ( 95% O₂ + 5% CO₂) had to be supplied for Vasu assuming that he was kept under the conditions of 27⁰C and normal atmospheric pressure?

Q. The molecular mass of $(N{H}_4{)}_{2}C{O}_3$ is:

1. 96 gm/mole
2. 98 gm/mole
3. 94 gm/mole
4. 80 gm/mole