I have 3 questions in chemistry. It is a multiple choice question so you have 4 options to choose from.?

Question

1.a student added dilute NaOH to test tuube containing zinc granules and heated the contents it was observed that
a) a colorless gas evolved
b) bubbles started risin up in test tbe
c) soltion remained colorless and transparent
d) zinc graules became red

2.After preparing slphur dioxide gas students are advised not to throw the contents of glass into the sink because the content would
a) damage the sink
b) react violently with water in sink
c) cause pollution
d) poisonous fumes

Answer 1

Questions from ExAmplary sample paper???U have ur exam on wednesday,pal?
Is this the time?
ANS:1.a
2.a

Answer 2

1. c
2. b

Answer 3

Sodium hydroxide has also been used in conjunction with zinc for creation of the famous "Gold pennies" experiment. When a penny is boiled in a solution of NaOH together with some granular zinc metal (galvanised nails are one source), the colour of the penny will turn silver in about 45 seconds. The penny is then held in the flame of a burner for a few seconds and it turns golden. The reason this happens is that granular zinc dissolves in NaOH to form Zn(OH)42-. This zincate ion becomes reduced to metallic zinc on the surface of a copper penny. Zinc and copper when heated in a flame form brass.

Sulfur dioxide is also used to make sulfuric acid, being converted to sulfur trioxide, and then to oleum, which is made into sulfuric acid. Sulfur dioxide for this purpose is made when sulfur combines with oxygen. This is called the contact process.

So d and a

Answer 4

The Answer Are :-
1.a)Colourless Gas Will Envolve
=>hydrogen gas will envolve
=>Sodium solution will be there
=>zinc metal will form
=>But Solution Will Be Colorless
2.d)poisonous Fume
=> Because it is Concentrated Can Cause Respiratory problems if inhaled and is very Harmful gas.

3nil)no question and answer are there

Answer 5

1. a,colorless gas evolved
bcoz, when zinc granules is added to NAOH then hydrogen gas evolved and this gas is colorless.

2. d, piosonous fumes
sulphur dioxide gas is poisonous in nature

Answer 6

for both questions, you try to add the value.

for eg. NaOH plus zinc granules and get the result (use the formula) and the result will be something like zinc hydroxide something, and usually it follows the first metal in the front which is now zinc. what color is zinc?

same for the second question.

Answer 7

1. a)a colorless gas evolved.
coz zinc reacts wid NaOH to form sod.zincate n hydrogen gas is evolved.

2. b) react violently with water in sink.
coz hot conc. sulphuric acid reacts violently wid water.

Answer 8

1. C
this is because NaOH and Zn does not react.

2. D
sulphur dioxide gas is really poisonous!

Answer 9

Where is the 3rd question ?
1) No reaction of NaOH on Zn option (c)
2) Cause pollution option (c)

Answer 10

For 1).c.
Bcoz zinc doesn't react with alkalies.
For 2).b.
Bcoz it can form oleum( a form of sulphuric acid)with water.