Alloys

Q. How much gold is present in 22 carat gold piece.

Q. Difference between 22 carat and 24 carat gold

Q.

What are the raw materials used in manufacturing cement?

1. Limestone

2. Clay

3. Iron

4. All of these

Q. Iron is mixed with carbon, nickel and chromium to form the alloy called ______.

1. brass
2. bronze
3. stainless steel
4. aluminium oxide

Q.

Two or more metals combine together to form an alloy which is a/an ____.

1. element

2. compound

3. homogeneous mixture

4. heterogeneous mixture

Q. Copper and _______ are the main constituents of bronze.

1. tin
2. chromium
3. carbon
4. magnesium

Q.

The reason for using aluminum in the alloy duralumin is:

1. Aluminum is brittle.

2. Aluminum gives strength.

3. Aluminum brings lightness.

4. Aluminum lowers melting point.

Q.

22-carat gold is preferred over 24-carat gold for making gold ornaments.

1. True

2. False

Q.

Which among the following alloys contain mercury as one of its constituents?

1. Stainless steel

2. Alnico

3. Solder

4. Zinc amalgam

Q.

Write true or false for the following statements:steel is an alloy of iron and alumunium

1. True
2. False

Q.

Assertion:- An alloy of gold with copper or silver is used to make ornaments.

Reason:- Pure gold is soft due to which it cannot be not used to make ornaments.

1. Assertion:- False

   Reason:- False

2. Assertion:- True

   Reason:- True

   Reason is the correct explanation of assertion

3. Assertion:- True

   Reason:- False

   Reason is not the correct explanation of assertion

4. Assertion:- False

   Reason:- True

Q. An alloy is an example of a/an ______.

1. element
2. mixture
3. compound
4. metalloid

Q. Alloy is an example of ________ mixture.

1. gas-gas
2. liquid-liquid
3. solid-solid
4. solid-liquid

Q.

28. State whether the following statement is true or false.

“Stainless steel is an alloy of iron.”

1. True
2. False

Q.

Alloys are a homogenous mixture of –

1. Metals only

2. non-metals only

3. Metals or a metal and non-metal

4. None of these

Q.

What is an amalgam. How does an amalgam differ from an alloy

Q.

Name the following

Two metals that form Solder

Q. The major component in steel is iron:

1. True
2. False

Q. How many carats is pure gold?

1. $22$ carats
2. $24$ carats
3. $23$ carats
4. $100$ carats

Q. A jewellery is selling 22-carat gold articals with 95% purity, it is approximately:

1. 3.5% higher
2. 3.5% lower
3. exact
4. 5% lower

Q. Why we use a platinum iridium alloy in making prototype meter and kilogram?

Q. Leaching of gold is done by which compound?

1. $NaCN$
2. By both $\left(a\right)$ and $\left(b\right)$
3. $KCN$
4. $Zn{CN}_2$

Q. Brass is an alloy of :

1. Zinc & carbon
2. Carbon & iron
3. Copper & iron
4. Copper & zinc

Q. Assertion :Amalgam is an alloy. Reason: An amalgam is a substance formed by the reaction of mercury with another metal.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. The addition of high proportions of manganese makes steel useful in making rails or railroads because manganese:

1. gives hardness to steel
2. helps in the formation of oxides of iron
3. can remove oxygen and sulphur
4. can show the highest oxidation state of $+7$

Q. Which one is an alloy of iron, chromium and nickel?

1. Stainless steel
2. Steel
3. Duralumin
4. Bronze

Q. 18 carat gold is .......... % pure.

Q. [TBQ.4(b)]
What are the metals that make the alloys brass and bronze?

Q. Mrs. Sharma has gone to the jewellers shop to buy gold jewellery. She asks the jeweller, if the jewellery of pure gold. The jewe;;er assure her than is is 100% gold and nothing has been mixed in it. Mrs. Sharma is happy and buys the necklace.
Answer the following questions based on the above situation:
What precautions should you take, while purchasing gold jewellery?

Q. The carbon content in steel is:

1. $0.21$ to $0.25\%$
2. $2$ to $2.5\%$
3. $0.25$ to $2\%$
4. $5$ to $8\%$