Worksheet

1.

Convert the following into basic units: (ii) 15.15 pm

2.

If the speed of light is $3.0 \times 10^8 m s^{-1}$, calculate the distance covered by light in 2.00 ns.

3.

Convert the following into basic units: (iii) 25365 mg

4.

How many significant figures are present in the following? (iv) 126,000

5.

What is the concentration of sugar ($C_{12}H_{22}O_{11}$) in $mol L^{-1}$ if its 20 g are dissolved in enough water to make a final volume up to 2L?

6.

In a solution major part of it is consist of solute particles

a. True b. False

7.

If the density of methanol is 0.793 kg $L^{-1}$, what is its volume needed for making 2.5 L of its 0.25 M solution?

8.

Calculate the amount of carbon dioxide that could be produced when (i) 1 mole of carbon is burnt in air.

9.

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

a. 1 g Au (s) b. 1 g Na (s) c. 1 g Li (s) d. 1 g of $Cl_2(g)$

10.

In a reaction $A + B_2 \rightarrow AB_2$ Identify the limiting reagent, if any, in the following reaction mixtures. (ii) 2 mol A + 3 mol B

11.

How many significant figures are present in the following? (v) 500.0

12.

Calculate the number of atoms in each of the following (iii) 52 g of He.

13.

How many significant figures are contained in each of the following measurements?

(a) 53 cm

(b) 2.05× 108m

(c) 86,002 J

(d) 9.740× 104m/s

(e) 10.0613 m3

(f) 0.17 g/mL

(g) 0.88400 s

a.

2,3,5,4,3,2,5

b.

2,3,5,4,6,2,4

c.

2,3,5,3,6,2,5

d.

2,3,5,4,6,2,5

14.

Express the following in the scientific notation: (i) 0.0048

15.

How many significant figures are present in the following? (ii) 208

16.

Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation:
$N_2 (g) + H_2 (g) \rightarrow 2NH_3 (g)$
(i) Calculate the mass of ammonia produced if $2.00 \times 10^3$ g dinitrogen reacts with $1.00 \times 10^3$ g of dihydrogen.

17.

A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives 3.38 g carbon dioxide, 0.690 g of water and no other products. A volume of 10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Calculate (i) empirical formula

18.

A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives 3.38 g carbon dioxide, 0.690 g of water and no other products. A volume of 10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Calculate (ii) molar mass of the gas

19.

How many significant figures are present in the following? (iii) 5005

20.

Express the following in the scientific notation: (ii) 234,000