Test: Laws of chemical combination

Question 1

The percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (atomic weight =78.4). Then minimum molecular weight of peroxidase anhydrous enzyme is

Accepted Answer

Answer

Answer

Answer

Question 2

The number of water molecules present in a drop of water (volume 0.0018 mL) density = 1g mL⁻¹ at room temperature is

Accepted Answer

Answer

Answer

Answer

Question 3

A mixture of and gas "Y" mol. mass 80 in the mole ratio a has a mean molecular mass 40. What would be mean molecular mass, if the gases are mixed in the ratio a under, identical conditions? (Assume that gases are non-reacting):

Accepted Answer

72

Answer

40

Answer

48

Answer

62

Question 4

If molecules are removed from of , then the number of moles of left are

Accepted Answer

Answer

Answer

Answer

Question 5

Arrange the following in the order of increasing mass (atomic mass: O = 16, Cu = 63, N = 14)
I. one atom of oxygen
II. one atom of nitrogen
III. mole of oxygen
IV. mole of copper

Accepted Answer

Answer

Answer

Answer

Question 6

Complete combustion of 0.858 g of compound X gives 2.64 g of CO₂ and 1.26 g of H₂O. The lowest molecular mass X can have:

Accepted Answer

43 g

Answer

86 g

Answer

129 g

Answer

172 g

Question 7

When burnt in air, 14.0 g mixture of carbon and sulphur gives a mixture of CO₂ and SO₂ in the volume ratio of 2:1, volume being measured at the same conditions of temperature and pressure moles of carbon in the mixture is

Accepted Answer

Answer

Answer

Answer

Question 8

1.12 mL of a gas is produced at S.T.P. by the action of 4.12mg of alcohol ROH with methyl magnesium Iodide. The molecular mass of alcohol is

Accepted Answer

Answer

Answer

Answer

Question 9

1 mole of mixture of CO and CO₂ requires exactly 28 gKOH in solution for complete conversion of all the CO₂ into K₂CO₃. How much amount more of KOH will be required for conversion into K₂CO₃ if one mole of mixture is completely oxidized to CO₂.

Accepted Answer

Answer

Answer

Answer

Question 10

1 mL of water has 25 drops. Let N₀ be the Avogadro number. What is the number of molecules present in 1 drop of water ? (Density of water = 1 g/mL)

Accepted Answer

Answer

Answer

Answer

Question 11

A 25.0 mm×40.0 mm piece of gold foil is 0.25 mm thick. The density of gold is 19.32 g/cm³. How many gold atoms are in the sheet? (Atomic weight : Au = 197.0)

Accepted Answer

Answer

Answer

Answer

Question 12

of and of are made to react completely to yield a mixture of and Calculate moles of ICl and formed

Accepted Answer

Answer

Answer

Answer

Question 13

The largest number of molecules is in

Accepted Answer

<img src="https://cn.edurev.in/ApplicationImages/Temp/6f21a99a-d6ad-4b94-ad30-0ed7814d8b85_lg.png" /> of water

Answer

of carbon monoxide

Answer

of ethyl alcohol

Answer

of nitrogen pentoxide

Question 14

of oxygen contains number of atoms equal to that in

Accepted Answer

<img src="https://cn.edurev.in/ApplicationImages/Temp/6ce1e473-315a-4c97-a4d1-2d19cd1b54b1_lg.png" /> of sulphur

Answer

of hydrogen

Answer

7 g of nitrogen

Answer

<img src="https://cn.edurev.in/ApplicationImages/Temp/6dbb9b50-8d0b-4caf-b62a-5d8aa2cf181f_lg.png" /> of sodium

Question 15

If we consider that

, in place of

, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of the substance will

Accepted Answer

remain unchanged

Answer

be a function of the molecular mass of the substance

Answer

increase two fold

Answer

decrease twice

Laws of chemical combination - Free MCQ Practice Test with solutions, JEE

MCQ Practice Test & Solutions: Test: Laws of chemical combination (15 Questions)

The percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (atomic weight =78.4). Then minimum molecular weight of peroxidase anhydrous enzyme is

The number of water molecules present in a drop of water (volume 0.0018 mL) density = 1g mL⁻¹ at room temperature is

A mixture of and gas "Y" mol. mass 80 in the mole ratio a has a mean molecular mass 40. What would be mean molecular mass, if the gases are mixed in the ratio a under, identical conditions? (Assume that gases are non-reacting):

If molecules are removed from of , then the number of moles of left are

Arrange the following in the order of increasing mass (atomic mass: O = 16, Cu = 63, N = 14)
I. one atom of oxygen
II. one atom of nitrogen
III. mole of oxygen
IV. mole of copper

Complete combustion of 0.858 g of compound X gives 2.64 g of CO₂ and 1.26 g of H₂O. The lowest molecular mass X can have:

Step 1: Determine the number of moles of CO₂ and H₂O produced.

Step 2: Determine the number of moles of Carbon and Hydrogen.

Step 3: Find the simplest ratio of C to H.

Step 4: Write the empirical formula.

Step 5: Calculate the molecular mass of C₃H₇.

Conclusion:

When burnt in air, 14.0 g mixture of carbon and sulphur gives a mixture of CO₂ and SO₂ in the volume ratio of 2:1, volume being measured at the same conditions of temperature and pressure moles of carbon in the mixture is

1.12 mL of a gas is produced at S.T.P. by the action of 4.12mg of alcohol ROH with methyl magnesium Iodide. The molecular mass of alcohol is

1 mole of mixture of CO and CO₂ requires exactly 28 gKOH in solution for complete conversion of all the CO₂ into K₂CO₃. How much amount more of KOH will be required for conversion into K₂CO₃ if one mole of mixture is completely oxidized to CO₂.

1 mL of water has 25 drops. Let N₀ be the Avogadro number. What is the number of molecules present in 1 drop of water ? (Density of water = 1 g/mL)

A 25.0 mm×40.0 mm piece of gold foil is 0.25 mm thick. The density of gold is 19.32 g/cm³. How many gold atoms are in the sheet? (Atomic weight : Au = 197.0)

of and of are made to react completely to yield a mixture of and Calculate moles of ICl and formed

The largest number of molecules is in

of oxygen contains number of atoms equal to that in

If we consider that , in place of , mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of the substance will

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Laws of chemical combination - Free MCQ Practice Test with solutions, JEE

MCQ Practice Test & Solutions: Test: Laws of chemical combination (15 Questions)

The percentage of Se in peroxidase anhydrous enzyme is 0.5% by weight (atomic weight =78.4). Then minimum molecular weight of peroxidase anhydrous enzyme is

The number of water molecules present in a drop of water (volume 0.0018 mL) density = 1g mL−1 at room temperature is

A mixture of and gas "Y" mol. mass 80 in the mole ratio a has a mean molecular mass 40. What would be mean molecular mass, if the gases are mixed in the ratio a under, identical conditions? (Assume that gases are non-reacting):

If molecules are removed from of , then the number of moles of left are

Arrange the following in the order of increasing mass (atomic mass: O = 16, Cu = 63, N = 14) I. one atom of oxygen II. one atom of nitrogen III. mole of oxygen IV. mole of copper

Complete combustion of 0.858 g of compound X gives 2.64 g of CO2 and 1.26 g of H2O. The lowest molecular mass X can have:

Step 1: Determine the number of moles of CO₂ and H₂O produced.

Step 2: Determine the number of moles of Carbon and Hydrogen.

Step 3: Find the simplest ratio of C to H.

Step 4: Write the empirical formula.

Step 5: Calculate the molecular mass of C₃H₇.

Conclusion:

When burnt in air, 14.0 g mixture of carbon and sulphur gives a mixture of CO2 and SO2 in the volume ratio of 2:1, volume being measured at the same conditions of temperature and pressure moles of carbon in the mixture is

1.12 mL of a gas is produced at S.T.P. by the action of 4.12mg of alcohol ROH with methyl magnesium Iodide. The molecular mass of alcohol is

1 mole of mixture of CO and CO2 requires exactly 28 gKOH in solution for complete conversion of all the CO2 into K2CO3. How much amount more of KOH will be required for conversion into K2CO3 if one mole of mixture is completely oxidized to CO2.

1 mL of water has 25 drops. Let N0 be the Avogadro number. What is the number of molecules present in 1 drop of water ? (Density of water = 1 g/mL)

A 25.0 mm×40.0 mm piece of gold foil is 0.25 mm thick. The density of gold is 19.32 g/cm3. How many gold atoms are in the sheet? (Atomic weight : Au = 197.0)

of and of are made to react completely to yield a mixture of and Calculate moles of ICl and formed

The largest number of molecules is in

of oxygen contains number of atoms equal to that in

If we consider that , in place of , mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of the substance will

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About this JEE Practice Test

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The number of water molecules present in a drop of water (volume 0.0018 mL) density = 1g mL⁻¹ at room temperature is

Arrange the following in the order of increasing mass (atomic mass: O = 16, Cu = 63, N = 14)
I. one atom of oxygen
II. one atom of nitrogen
III. mole of oxygen
IV. mole of copper

Complete combustion of 0.858 g of compound X gives 2.64 g of CO₂ and 1.26 g of H₂O. The lowest molecular mass X can have:

When burnt in air, 14.0 g mixture of carbon and sulphur gives a mixture of CO₂ and SO₂ in the volume ratio of 2:1, volume being measured at the same conditions of temperature and pressure moles of carbon in the mixture is

1 mole of mixture of CO and CO₂ requires exactly 28 gKOH in solution for complete conversion of all the CO₂ into K₂CO₃. How much amount more of KOH will be required for conversion into K₂CO₃ if one mole of mixture is completely oxidized to CO₂.

1 mL of water has 25 drops. Let N₀ be the Avogadro number. What is the number of molecules present in 1 drop of water ? (Density of water = 1 g/mL)

A 25.0 mm×40.0 mm piece of gold foil is 0.25 mm thick. The density of gold is 19.32 g/cm³. How many gold atoms are in the sheet? (Atomic weight : Au = 197.0)