WorksheetsDisciplinary Core Ideas of Chemistry
Total questions: 9
Worksheet time: 41mins
Which of the following statements about a compound is incorrect?
(a) A molecule of a compound has atoms of different elements.
(b) A compound cannot be separated into its constituent elements by physical methods of separation.
(c) A compound retains the physical properties of its constituent elements.
(d) The ratio of atoms of different elements in a compound is fixed
16 g of oxygen has same number of molecules as in [atomic mass of O=16, C=12, N=14, H=1]
(a) 16 g of CO
(b) 28 g of N2
(c) 14 g of N2
(d) 1.0 g of H2
One atomic mass unit (amu) is closest to the mass of:
The oxygen-16 nucleus
The carbon-12 nucleus
6.022 x 1023 atoms of hydrogen
One proton
The unit of amount of substance is:
ampere
second
mole
kilogram
The law of multiple proportions was proposed by (a)
Law of constant proportion states that
matter can neither be created nor destroyed
equal volumes of gases at the same temperature and pressure should contain equal number of molecules.
a given compound always contains exactly the same proportion of elements by weight.
if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element, are in the ratio of small whole numbers
How much copper can be obtained from 100 g of copper sulphate (CuS04)? [atomic mass of Cu=63.5, S=32, O=16]
63.5g
39.8g
159.5g
35.8g
What is the concentration of sugar (C12H22O11) in mol L -1 if its 20 g are dissolved in enough water to make a final volume up to 2 L?
0.058 mol/ L
10 mol /L
0.0058 mol / L
0.029 mol/L
Chlorine is prepared in the laboratory by treating manganese dioxide (Mn02) with aqueous hydrochloric acid according to the reaction
4HCI(aq) + MnO2(s) → 2H2O(I) + MnCI2(aq) + Cl2(g)
How many grams of HCI react with 5.0 g of manganese dioxide? [atomic mass of Mn=55, O=16, H=1, Cl=35.5u]
8.4g
9.2g
5.4g
10.5g
