|
(i) Account for the following: 1. White silver chloride turns grey in sunlight
|
|
1
|
16821
|
March 28, 2019
|
|
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining?
|
|
1
|
2747
|
March 28, 2019
|
|
Why do we store silver chloride in dark coloured bottles which are also called as amber bottles?
|
|
1
|
992
|
March 28, 2019
|
|
Define oxidation and reduction?
|
|
1
|
671
|
March 28, 2019
|
|
What are exothermic and endothermic reactions?
|
|
1
|
916
|
March 28, 2019
|
|
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?
|
|
1
|
4946
|
March 28, 2019
|
|
When you mix solutions of lead (II) nitrate and potassium iodide
|
|
1
|
33216
|
March 28, 2019
|
|
(i) Name the products formed when sodium hydrogen carbonate is heated
|
|
1
|
805
|
March 28, 2019
|
|
Define a combination reaction. Give one example of a combination reaction which is also exothermic
|
|
1
|
1885
|
March 28, 2019
|
|
(i) What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube?
|
|
1
|
4309
|
March 28, 2019
|
|
(a) What is the colour of ferrous sulphate crystals? How does this colour change after heating?
|
|
1
|
2642
|
March 28, 2019
|
|
Why do silver articles turn black and copper items turn green after some time?
|
|
1
|
2240
|
March 28, 2019
|
|
Give an example of a decomposition reaction. Describe an activity to illustrate such a reaction by heating?
|
|
1
|
2541
|
March 28, 2019
|
|
Zinc reacts with hydrochloric acid according to the reaction equation:
|
|
0
|
964
|
March 24, 2018
|