Preparation from Cold Water and Metals

Q.

K, Ca, Na, Mg, Al, Zn, Fe, Pb, Cu, Ag. Name metal

(i) Which will displace hydrogen from cold water

Q. Magnesium reacts with steam to produce magnesium oxide and .

1. hydrogen gas
2. oxygen gas
3. magnesium hydride

Q.

Which of the following metals can displace hydrogen from cold water?

1. $\mathrm{Ca}$

2. $\mathrm{Au}$

3. $\mathrm{Sb}$

4. $\mathrm{Sn}$

Q. Magnesium reacts with steam to produce magnesium oxide and .

1. hydrogen gas
2. oxygen gas
3. magnesium hydride

Q.

Name a metal attacked by cold water, hot water and and steam.

Q.

Which of the following reactions will result in the formation dihydrogen gas?

1. A reaction of potassium with cold water.

2. A reaction of sodium with cold water.

3. A reaction of sodium with oxygen.

4. A reaction of potassium with oxygen.

Q. Which of the following statements are true regarding the reaction of metals with water?

1. All metals react with water.
2. Magnesium reacts with cold water.
3. Magnesium reacts with steam.
4. Potassium reacts with cold water.

Q. In electrolysis electric current is passed through which state of compound to bring about a chemical change?

1. Aqueous solution or solid state
2. Aqueous solution or molten state
3. Aqueous solution or gaseous state
4. Gaseous state

Q. Naina dropped a piece of metal into cold water. She observed that after a while it started floating. The metal Naina used is .

1. Calcium
2. Magnesium
3. Sodium
4. Zinc

Q.

How do active metals like Sodium, Potassium, and Calcium react with water? Explain your observation.

Q.

What is the decreasing order of reactivity of the following metals? $\mathrm{Na},\mathrm{Al},\mathrm{K},\mathrm{Cu},\mathrm{Ag},\mathrm{Fe}$

1. $\mathrm{Na}>\mathrm{K}>\mathrm{Al}>\mathrm{Cu}>\mathrm{Ag}>\mathrm{Fe}$

2. $\mathrm{K}>\mathrm{Na}>\mathrm{Al}>\mathrm{Cu}>\mathrm{Fe}>\mathrm{Ag}$

3. $\mathrm{K}>\mathrm{Na}>\mathrm{Al}>\mathrm{Fe}>\mathrm{Cu}>\mathrm{Ag}$

4. $\mathrm{K}>\mathrm{Na}>\mathrm{Al}>\mathrm{Fe}>\mathrm{Ag}>\mathrm{Cu}$

Q.

Which of the following is/are salient features of the activity series?

1. Electropositive character reduces down the series

2. A salt of a metal higher up in the series is displaced by lower metal

3. Reducing power of metals decreases down the group

4. The tendency of metal to lose electrons decreases down the group.

Q. Granules of zinc react with dilute hydrochloric acid to liberate a gas that burns with the pop sound. The gas is:

1. oxygen
2. hydrogen
3. carbon dioxide
4. carbon monoxide

Q. Assertion: Sodium reacts vigorously with cold water but magnesium does not react with cold water.
Reason: Sodium is more reactive than magnesium.

1. Assertion: True, Reason: False
   
   Reason is not the correct explanation of assertion.

2. Assertion: False, Reason: False

3. Assertion: False, Reason: True

4. Assertion: True, Reason: True
   
   Reason is the correct explanation of assertion.

Q. Which of these metals react with water in any form (steam, hot water and cold water)?

1. $Na$
2. $K$
3. $Pb$
4. $Au$
5. $Al$
6. $Mg$
7. $Ca$
8. $Ag$

Q.

Which of the following reacts vigorously with cold water?

1. Sodium (Na)

2. Calcium (Ca)

3. Aluminium (Al)

4. Zinc (Zn)

Q. Match the metals with the state of water that they react with.

1. Iron
2. Magnesium
3. Sodium
4. Lead
5. No reaction
6. Steam
7. Hot water
8. Cold water

Q. Choose the correct option to complete the following reaction:

$2\text{Al (s)}+6\text{HCl (aq)}\to$

1. $2{\text{AlH}}_3\text{(aq)}+3{\text{Cl}}_2\text{(g)}$
2. ${\text{Al}}_2{\text{O}}_3\text{(aq)}+3{\text{H}}_2\text{(g)}$

3. $2{\text{Al(OH)}}_3\text{(aq)}+3{\text{Cl}}_2\text{(g)}$

4. $2{\text{AlCl}}_3\text{(aq)}+3{\text{H}}_2\text{(g)}$

Q. Identify the metal which reacts most easily with a base:

1. Gold
2. Iron
3. Potassium
4. Zinc

Q. What is the observation that can be made when calcium reacts with $H_{2}O$?

1. Vigorous reaction
2. Calcium floats on water
3. Calcium does not react at all
4. Explosive reaction

Q. Molten is used for coating iron in galvanisation.

1. copper
2. lead
3. zinc
4. iron

Q. Molten is used for coating iron in galvanisation.

1. zinc
2. iron
3. copper
4. lead