Question 1- When a candle burns both physical and chemical changes occurs. Identify these changes,and Explain.
Question 2- What is crystallization? How crystals of copper sulphate are prepared.
Question 3- What is galvanization? How it is done.
Question 4- What is the composition of stainless steel and what is the formula of Eno.
Question 5- State four difference between acid and bases, Name to acid and two bases.
Question 6- Explain why an antacid tablet is taken when you suffer from acidity. Write the reaction also.
Question 7- Describe the process of Neutralisation with the help of an example.
Question 8- Discuss why wearing more layers of clothing during the winter keep us warmer than wearing just one thick piece of clothing.
Question 9- Explain Land and Sea breeze with the help of diagram.
Question 10- What are conductors and Insulator. Give different modes of transfer of heat in solid, liquid and gas.
Answers
Answer:
1. “I’m sick of following my dreams, man. I’m just going to ask where they’re going and hook up with ’em later.”
—Mitch Hedberg
2. “Gentlemen, you can’t fight in here. This is the war room.”
—President Merkin Muffley (Peter Sellers), Dr. Strangelove
3. “My mother always used to say: The older you get, the better you get, unless you’re a banana.”
—Rose (Betty White), The Golden Girls
Answer:
When a candle burns, both physical & chemical changes occur. On heating, candle wax melts and form liquid wax. It is a physical change. Since it again turns into solid wax on cooling.
Crystallization is the process by which we can obtain crystals of copper sulphate. In this process, a few drops of dilute sulphuric acid is added to water. The water is then boiled & as it starts boiling, copper sulphate powder is added with stirring. The powder must be added on till the solution becomes saturated.
Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc.
Stainless steels are steels containing at least 10.5% chromium, less than 1.2% carbon and other alloying elements. Stainless steel's corrosion resistance and mechanical properties can be further enhanced by adding other elements, such as nickel, molybdenum, titanium, niobium, manganese, etc.The ENO is made up of sodium hydrogen carbonate(NaHCO3), citric acid(C6H8O7 ) and sodium carbonate( Na2CO3) and acts as a popular antacid in practical use.
see the image for answer 5 citric acid nitric acid are bases and sodium hydroxide calcium hydroxide are based
Acidity is caused due to the excess production of acids in the stomach. An antacid tablet contains bases, such as milk of magnesia(magnesium hydroxide, gelusil,etc. These bases react with excess of acids and neutralize the effect of excessive acid and brings relief.
acid + base = salt + water
