Avogadro's Number

Q.

Which of the following contains the largest number of atoms?

1. $11\mathrm{g}\mathrm{of}{\mathrm{CO}}_2$

2. $4\mathrm{g}\mathrm{of}{\mathrm{H}}_2$

3. $5\mathrm{g}\mathrm{of}{\mathrm{NH}}_3$

4. $8\mathrm{g}\mathrm{of}{\mathrm{SO}}_2$

Q.

How do you calculate $1\mathrm{amu}$in grams using the ${\mathrm{C}}_{12}$ atom?

Q.

Calculate the number of molecules in 100 ml of water

Q. How many molecules are present in 9g of water?

1. 6.022$\times$ ${10}^{23}$
2. 3.011$\times$ ${10}^{23}$
3. 6.022$\times$ ${10}^{25}$
4. 3.011$\times$ ${10}^{20}$

Q. Which of the following correctly represents 360 g of water?

1. 2 moles of water
2. 20 moles of water
3. $1.2044\times {10}^{24}$ molecules of water
4. $1.2044\times {10}^{25}$ molecules of water

Q.

The mass of a single atom of an element X is $2.65\times {10}^{-23}$ g.What could this element be?

1. Nitrogen

2. Oxygen

3. Hydrogen

4. Phosphorus

Q.

Calculate the no of molecules present in one kg of calcium chloride

Q.

What volume of CO2 will contain same number of molecules as are present in 16 gram of oxygen

Q.

Calculate the number of molecules in 3/2 litres of water.

Q.

.${10}^{22}$atoms of an element X arefound to have a mass of 930 mg. Calculate the molar massof the element ‘X’.

Q.

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

1. 1770.51 g

2. 1440.71 g

3. 1540.71 g
4. 1420.91 g

Q.

Which has more atoms 200 g of argon or 200 g of neon?

__

Q.

Calculate the number of sodium and carbon atoms in 8 grams of sodium carbonate $\left(N{a}_{2}C{O}_3\right)$.

1. Sodium atoms - $0.9\times {10}^{23}$

   Carbon atoms - $0.45\times {10}^{23}$

2. Sodium atoms - $20\times {10}^{23}$

   Carbon atoms - $5\times {10}^{23}$

3. Sodium atoms - $1\times 6\times {10}^{23}$

   Carbon atoms - $5\times {10}^{23}$

4. Sodium atoms - $4\times {10}^{23}$

   Carbon atoms - $5\times {10}^{23}$

Q.

Which of the following contain the largest number of molecules?

1. 40 g of ${\mathrm{H}}_{2_{}}$

2. 4 moles of ${\mathrm{SO}}_2$

3. 35.5 g of ${\mathrm{Cl}}_2$

4. 40 g of ${\mathrm{O}}_2$

Q.

What is the value of Avogadros constant?

Q. calculate the number of moles of methane in 0.8g so methane

Q. Calculate the number of oxygen atoms in 3.2 g of $H_2{\mathrm{SO}}_4$? (3 marks)

Q.

Which one of the following will have the largest number of atoms?

1. 1 g Au(s)

2. 1 g Na(s)

3. 1 g Li(s)

4. 1 g ${\mathrm{Cl}}_2$(s)

Q. calculate the no of atoms of each element in 0.18 g of glucose

Q.

Choose the correct option:

1. Moles = Given mass/ molar mass.

2. Moles = Given volume/ 22.4 liters

3. Moles = Given number of particles / Avogadro number

4. All the given options are correct

Q.

1 mole of anything is equal to ______ in number.

1. 6.022 × 10²³

2. 6.022 × 10²¹

3. 7.022 × 10²³

4. 6.022 × 10²²

Q. How to determine the number of molecules in 18 ml of water

Q. how many molecules of aspirin (molar mass=180u)are present in 50mg tablet?

Q. How many moles of sodium chloride present in 250 ml of a 0.50 M NaCl solution?

Q. Calculate the number of molecules in 54 gm of $H_{2}O$.

Q.

A MIXTURE CONTAINS 0.2 GRAMS OF OXYGEN GAS AND 0.4 GRAM OF CARBON DIOXIDE GAS . THE RATIO OF OXYGEN ATOMS PRESENT IN OXYGEN GAS TO THAT IN CARDON DIOXIDE GAS IS?

Q.

A flask conntains 3.2g of sulphur dioxide calculate the following

1.the moles of sulphur dioxide present inthe flask

2.the number of molecules of sulphurdioxide present in the flask

3 the volume occupied by 3.2g of sulphur dioxide at s.t.p[s=32, o=16]

Q. The number of molecules in 5.65 g of ammonia is approximately x*10 raise to 23.what is the value of x

Q.

Calculate the number of water molecules in 0.06 grams of water.