What are polyatomic ions? Give examples. - Science

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of acetic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium acetate. Show that these observations are in agreement with the law of conservation of mass.

Sodium carbonate + acetic acid \rightarrow sodium acetate + carbon dioxide + water

Hydrogen and oxygen combine in the ratio of 1:8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?

Which postulate of Dalton's atomic theory is the result of the law of conservation of mass?

Which postulate of Dalton's atomic theory can explain the law of definite proportions?

Define the atomic mass unit.

Why is it not possible to see an atom with naked eyes?

1. Write down the formulae of
(i) sodium oxide
(ii) aluminium chloride
(iii) sodium sulphide
(iv) magnesium hydroxide

2. Write down the names of compounds represented by the following formulae:
(i)\text{Al}_2(\text{SO}_4)_3
(ii) \text{CaCl}_2
(iii) \text{K}_2\text{SO}_4
(iv) \text{KNO}_3
(v) \text{CaCO}_3.

What is meant by the term chemical formula?

How many atoms are present in a
(i) \text{H}_2\text{S} molecule and
(ii) \text{PO}_4^{3-} ion?