chemistry (practical)

Question 1

3 golden rules of acid

Answer 1

1) metal + acid= salt + hydrogen
2) metal carbonate + acid= salt + co2 + h2o
3) alkali/ hydroxide + acid= salt + h2o

Question 2

white solid add to solution

Answer 2

it is a carbonate- dissolve form XX color solution - effervescence occurs with colorless and odorless gas being evolved- white precipitate is formed in limewater (gas released is co2)

Question 3

black solid add to solution

Answer 3

it is an oxide- dissolves form XX color solution, no effervescence- test tube feels warm

Question 4

silvery grey solid added to solution

Answer 4

it is a metal- dissolve form XX color solution- effervescence occurs with colorless and odorless gas being evolved- gas released is hydrogen

Question 5

co2 test

Answer 5

effervescence occurs with colorless and odorless gas being evolved. when bubbled into limewater, white precipitate is formed

Question 6

hydrogen test

Answer 6

effervescence occurs with colorless and odorless gas being evolved. when a lighted splint is held above the test tube containing the gas, it is extinguished with a “pop” sound.

Question 7

blue litmus paper in acid

Answer 7

turns red

Question 8

red litmus paper in alkali

Answer 8

turns blue

Question 9

universal indicator in acid

Answer 9

red orange yellow (depending on concentration)

Question 10

universal indicator in alkali

Answer 10

dark green blue purple (depending on concentration)

Question 11

universal indicator neutral

Answer 11

green