Question

1) Write the principle of a chemical equation?
2) Name the elements represented by the following symbols.
a) K b) Na c). Pb d) Br
3) Fill in the blanks.
i. NaCl+ _ HCl +NaNO3
ii NaOH+ _ NaCl + _
iii. CuO+ _ cucl2+_ ​

Answer 1

Answer :

1. Write the principle of a chemical equation.

• The chemical equation should obey the law of conservation of mass [energy can neither be created nor destroyed, but can only be transferred from one form to another].
• The mass of reactants must be equal to the mass of products.

2. Name the elements represented by the following symbols.

• a) K - Potassium [K-Kalium]
• b) Na - Sodium
• c) Pb - Lead [Plumbum]
• d) Br - [Bromine]

3. Fill in the blanks.

i. NaNO3 + HCl → NaCl + HNO3. [Already balanced]

ii. NaOH + HCl → NaCl + H2O [Already balanced]

iii. CuO + 2HCl → CuCl2 + H2O