Question

Answer this questions

Answer 1

Answer:

7. A. CaOH + CO2 → CaCO3 + H2O

2CaOH + CO2 → 2CaCO3 + H2O

B. Zn + AgNO3 → Zn(NO3)2 + Ag

Zn + 2AgNO3 → Zn(NO3)2 + 2Ag

C. Al + CuCl → AlCI3 + Cu

Al + 3CuCl → AlCI3 + 3Cu

D. KBr (aq) + BaI2 → KI + BaBr2

2KBr (aq) + BaI2 → 2KI + BaBr2

E. ZnCO3 → ZnO + CO2

ZnCO3 → ZnO + CO2 (already balanced so no need to)

1. C

2. A

3. Aluminium

4. A

5. A

6. C

Explanation:

Concepts used:

• Balancing equations means to correctly fulfil the amount of atoms or molecules on the left and right hand side of the equation as to correspond with Law of conservation of mass.
• You need to know chemical names, formulas and valencies of familiar metals that come in books and questions frequently (just practice and you will learn)
• Understand and memorise some common reactions like rusting of iron, silver etc.
• And most importantly, do not mug up but understand it, chemistry is all about understanding stuff. The more you mug up the more difficult it will get.

Good Luck!