Test for Detection of metal ions

During a science experiment, Hamna and Maryam were testing different gases. To identify hydrogen (H2), they observed:

• A glowing splint is extinguished.

• A glowing splint relights.

• A pop sound is heard when a burning splint is introduced.

• A blue flame is observed.

During a science experiment, Amna and Maryam were testing for the presence of oxygen (O2) in a test tube. What observation would confirm the presence of oxygen?

• a glowing splint relights

• a lit splint pops

• limewater turns milky

• a glowing splint extinguishes

During a chemistry class experiment, Zubaida and Maryam were asked to identify sulfur dioxide (SO2). The test they used was:

• using litmus paper

• using lime water

• using potassium dichromate paper

• using bromine water

Maryam and Minahil are conducting a qualitative analysis of salts in their chemistry lab. What do they need to identify?

• The color of the salt

• The cation and anion present

• The melting point of the salt

• The solubility of the salt

Hamna is conducting an experiment in her chemistry class. She needs to identify the chemical formula of ammonia for her project. What is the chemical formula of ammonia?

• NH3

• H2O

• CO2

• O2

Elham and Zubaida are conducting an experiment in their science class. In the Squeaky Pop Test, what is used to produce the 'pop' sound?

• The 'pop' sound in the Squeaky Pop Test is produced by a sudden release of pressure, typically from a gas or air trapped in a container.

• A chemical reaction between vinegar and baking soda.

• The striking of two metal objects together.

• The popping of a balloon.

Eshaal and Hamna are conducting an experiment in their science class. To test for oxygen, what should they use?

• A burning candle

• A glowing splint

• A piece of paper

• A matchstick

During a chemistry class experiment, Minahil and Eshaal observed a color change when filter paper wetted with potassium dichromate was exposed to the gas produced. What is the color change observed?

• Red to green

• Blue to yellow

• Green to blue

• Yellow to red

During a chemistry class experiment, Elham and Amna were testing different gases. What is the observation when ammonia (NH₃) is tested?

• turns damp red litmus paper blue.

• turns damp blue litmus paper red.

• produces a white precipitate with silver nitrate.

• gives off a pungent odor.