Question

B. Choose the correct options and fill in the blanks.
1. A chemical equation is the shorthand form of representing a chemical reaction using the
(names/symbols or formulae) of the reactants and products.
2. The gas evolved is indicated with a/an ..
(upward arrow/downward arrow)
in the chemical equation.
3. When blue copper sulphate crystals are heated, they become
(white/
black).
4. When ferrous sulphide is mixed with dilute acid, the smell of rotten eggs is given out. This
is due to the formation of
(ferric chloride/hydrogen sulphide).
.... (exothermic/
5. The reaction of quick lime and water to form slaked lime is an .....
endothermic) reaction.
6. The formation of water by the reaction of hydrogen and oxygen is a
(decomposition/combination)reaction..​

Answer 1

1) formula

2)an upward arrow

3) black

4)---

5) combination exothermic reaction

6) combination reaction

I don't know the 4th one answer

hope my answer would be helpful