Question

7.
8.
$what \: should \: be \:subtracted \: \: from \: 5xy {}^{2} - 10x {}^{2} {y}^{2} + 15 {x}^{2}{y} \: to \: get \: - 3 {x}^{2} {y}^{2} - {x}^{2} {y}^{2} - 8 {x}^{2}{y}$
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Answer 1

Step-by-step explanation:

Write a balanced chemical equation for process of photosynthesis. Name the

type of this chemical reaction.

Q.14. What is a redox reaction? When a magnesium ribbon burns in air with a

dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?

Q.15. Write any two observations in an activity which may suggest that a chemical

reaction has taken place. Give an example in support of your answer.

Q.16. What do you mean by exothermic and endothermic reactions? Give one

example of each type.

Section -III

Q.17. A white powder is added while baking breads and cakes to make them soft and

fluffy. Write the name of the powder. Name its main ingredients. Explain the function

of each ingredient. Write the chemical reaction taking place when the powder is

heated during baking.(ii) Write one use of washing powder.

Q.12. (a) Write the name given to bases that are highly soluble in water. Give an

example.

(b) How is tooth decay related to pH?

Q.13. Write a balanced chemical equation for process of photosynthesis. Name the

type of this chemical reaction.

Q.14. What is a redox reaction? When a magnesium ribbon burns in air with a

dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?

Q.15. Write any two observations in an activity which may suggest that a chemical

reaction has taken place. Give an example in support of your answer.

Q.16. What do you mean by exothermic and endothermic reactions? Give one

example of each type.

Section -III

Q.17. A white powder is added while baking breads and cakes to make them soft and

fluffy. Write the name of the powder. Name its main ingredients. Explain the function

of each ingredient. Write the chemical reaction taking place when the powder is

heated dur