Q5 of 24 Page 167

How many grams are there in the following?

i) 1 mole of chlorine molecule, Cl2


ii) 2 moles of sulphur molecules, S8


iii) 4 moles of ozone molecules, O3


iv) 2 moles of nitrogen molecules, N2

we know that when gases are present in the molecular form, 1 mole of any gas is equal to 6.023 x 1023 molecules of that gas, which is equal to the gram molecular weight of gas in the combined state.


(i) 1 mole of chlorine molecules contains 71 grams of Cl2. (2×35.5)


(ii) 2 moles of sulphur molecules contain 512 grams of S8. (2×32×8)


(iii) 4 moles of ozone molecules contain 192 grams of O3. (4× 16× 3)


(iv) 2 moles of nitrogen molecules contain 56 grams of N2. (2× 14× 2)


More from this chapter

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2

Nitro glycerine is used as an explosive. The equation for the explosive reaction is

4C3H5((NO3))312CO2 + 10H2O + 6N2 + O2


(l) (g) (l) (g) (g)


(Atomic mass of C = 12, H = 1, N = 14, O=16)


1. How many moles does the equation show for i) Nitroglycerine ii) gas molecules produced?


2. How many moles of gas molecules are obtained from 1 mole of nitroglycerine?


3. What is the mass of 1 mole of nitroglycerine?

 3

Sodium bi carbonate breaks down on heating:

2NaHCO3 Na2CO3 + H2O + CO2


(Atomic mass of Na = 23, C = 12, H = 1, O=16)


i) How many moles of sodium bi carbonate are there in the equation?


ii) What is the mass of sodium bicarbonate used in this equation?


iii) How many moles of carbon dioxide are there in this equation?

 4

40 g of calcium was extracted from 56 g of calcium oxide

(Atomic mass of Ca= 40, O=16)


i) What mass of oxygen is there in 56 g of calcium oxide?


ii) How many moles of oxygen atoms are there in this?


iii) How many moles of calcium atoms are there in 40 g of calcium?


iv) What mass of calcium will be obtained from 1000 g of calcium oxide?

 6

Find how many moles of atoms are there in:

i) 2 g of nitrogen.


ii) 23 g of sodium


iii) 40 g of calcium.


iv) 1.4 g of lithium


v) 32 g of sulphur.