Metals and Non-Metals — Science STD 10 — Question

Show the electronic transfer in the formation of MgCl₂, from its elements.

A first-aid manual suggests that vinegar should be used to treat wasp stings and baking soda for bee stings. What does this information tell you about the chemical nature of:

1. Wasp stings?
2. Bee stings?

What is an alloy? How is an alloy made?

Blue litmus solution is added to two test tubes A and B containing dilute HCl and NaOH solution respectively. In which test tube a colour change will be observed? State the colour change and give its reason.

A student adds a spoon full of powdered sodium hydrogen carbonate to a flask containing ethanol acid. List two main observations, he must note in his note book, about the reaction that takes place. Also write chemical equation for the reaction.

A first-aid manual suggests that vinegar should be used to treat wasp stings and baking soda for bee stings. What does this information tell you about the chemical nature of:

1. Wasp stings?
2. Bee stings?

A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.

The soil in a field is highly acidic. Name two materials which can be added to this soil to reduce its acidity. Give the reason for your choice.

Name the acids or alkalis used to make,

1. Car batteries.
2. Explosives.
3. Soaps.
4. Fertilisers..

What is the significance of atomic number in the modern classification of elements? Explain with the help of an example.