Mole Concept & Avogadro Number

Q.

Calculate the mass of O₂ molecule?

Q.

What is the mass of one molecule of oxygen?

Q.

Calculate the number of atoms in 52 u of $\mathrm{He}$.

Q.

What is the mass of one atom of $\mathrm{carbon}-12$ in grams?

Q.

If 16 g of oxygen contains 1 mole of oxygen atoms, calculate the mass of one atom of oxygen.

Q.

214.2 g of sugar syrup contains 34.2 g of sugar.

Calculate
(i) molarity of the solution
(ii) mole fraction of sugar in the syrup.

Q.

Which among the following has maximum mass?

1. $1\mathrm{g}$ of $\mathrm{Fe}$

2. $0.1$ mole of ammonia

3. ${10}^{22}$ atoms of carbon

4. ${10}^{22}$ molecules of carbon dioxide

Q.

How$0.50\mathrm{mol}{\mathrm{Na}}_2{\mathrm{CO}}_3$is different from$0.50\mathrm{M}{\mathrm{Na}}_2{\mathrm{CO}}_3$?

Q.

Question 9
3.42 g of sucrose are dissolved in 18g of water in a beaker. The number of oxygen atoms in the solution are
(a) $6.68\times {10}^{23}$
(b) $6.09\times {10}^{22}$
(c) $6.022\times {10}^{23}$
(d) $6.022\times {10}^{21}$

Q. The number of molecules in 34.0g of $N{H}_3$ is ____.

1. $36.12\times {10}^{23}$
2. $18.06\times {10}^{23}$
3. $12.04\times {10}^{23}$
4. $6.02\times {10}^{23}$

Q.

Calculate the number of moles in 9 grams of aluminium.

Q.

How do you determine the molar mass of helium?

Q. Calculate the percentage of nitrogen in nitric acid.

1. 
   $22.22\%$
2. 
   $21\%$
3. 
   $21.22\%$
4. 
   $22.8\%$

Q.

Calculate the number of moles for $12.044\times {10}^{23}$a number of $\mathrm{He}$ atoms (finding mole from number of particles).

Q.

Calculate the number of moles of magnesium present in a magnesium ribbon weighing $12\mathrm{g}$. The molar atomic mass of magnesium is $24\mathrm{g}{\mathrm{mol}}^{-1}$.

Q. Question 23
Calculate the number of moles of magnesium present in a magnesium ribbon weighing 12 g. Molar atomic mass of magnesium is $24gmo{l}^{-1}$.

Q. The percentage of carbon in ethanoic acid $\left(C{H}_{3}COOH\right)$ is

1. 
   $16\%$
2. 
   $40\%$
3. 
   $24\%$
4. 
   $60\%$

Q.

Calculate the number of moles in 2.2g of ${\mathrm{CO}}_2$.

Q.

Question 9(a)
What is the mass of:
(a)0.2 mole of oxygen atoms?

Q.

What is a gram molecule? And gram equivalent? Give an example

Q.

The molecular weight of Magnesium oxide is_______

Q.

Which of the following contains maximum number of molecules?

1. $1\mathrm{g}{\mathrm{CO}}_2$

2. $1\mathrm{g}{\mathrm{N}}_2$

3. $1\mathrm{g}{\mathrm{H}}_2$

4. $1\mathrm{g}{\mathrm{CH}}_4$

Q. Why 12 gram of carbon is 1 mole?Why not 1 gram of carbon?

Q. Question 5
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose $\left(C_{12}{H}_{22}{O}_{11}\right)$
(b) 2 moles of $C{O}_2$
(c) 2 moles of $CaC{O}_3$
(d) 10 moles of $H_{2}O$

Q.

Hemoglobin contains 0.33% of iron by weight. The molecular mass of hemoglobin is about 67200. The number of iron atoms (atomic mass of Fe = 56) present in a molecule of hemoglobin is?

Q.

What is the mass of one mole of water?

Q.

Calculate the percentage of magnesium in magnesium carbonate.

Q.

Question 1
If one mole of carbon atoms weighs 12 grams, what is the mass (in grams) of 1 atom of carbon?

Q. Calculate the number of moles for $3.011\times {10}^{23}$ He atoms.

1. 1 mol
2. 2 mol
3. 1.5 mol
4. 0.5 mol

Q.

How many grams are there in $5moles$ of oxygen ?