Model sample paper solution | class 8

Model test paper

Model test paper class 9

11th class English model paper solution

Factories class 8

An impure sample of sodium chloride that weighed 0.50 g gave 0.90 g of silver choride as precipitate on treatment with excess of silver nitrate solution. Calculate the percentage purity of the sample.

A sample of soil is mixed with water and allowed to settle .The clear supernatant solution turns the pH paper yellowish - orange . Which of the following would change the colour of this pH paper to greenish- blue?

12. g of an impure sample of arsenious oxide was dissolved in water containing 7.5 g of sodium bicarbonate and the resulting solution was diluted to 250 mL . 25 mL of this solution was completely oxidised by 22.4 mL of a solution of iodine. 25 mL of this iodine solution reacted with same volume of a solution containing 24.8 g of sodium thiosulphate (Na_(2)S_(2)O_(3).5H_(2)O) in one litre. Calculate teh percentage of arsenious oxide in the sample ( Atomic mass of As=74 )

A solution 'X' give orange colour when a drop of it falls on pH paper, while another solution 'Y' gives bluish colour when a drop of it falls on pH paper. What is the nature of both the solutoins? Determine the pH of solution 'X' and 'Y'?

Amongst the following, the total number of compounds whose aqueous solution turns red litmus paper blue is:

A student prepared solutions of (i) an acid and (ii) a base in two separate beakers. She forgot to label the solutions and litmus paper is not available in the laboratory. Since both the solutions are colourless how will she distinguish between the two ?