Atomic Mass

Q.

Calculate the formula unit mass of CaCl2.

Q.

One unified mass is equal to _____ grams.

Q.

What is the atomic mass of ${\mathrm{SO}}_4$?

Q.

On Combustion Of $25\mathrm{g}$ Of An Unknown Hydrocarbon Produces $88\mathrm{g}$ of ${\mathrm{CO}}_2$ and $9\mathrm{g}$ of ${\mathrm{H}}_2\mathrm{O}$. This Unknown Hydrocarbon Contains:

1. $18\mathrm{g}$ of carbon and $7\mathrm{g}$ of hydrogen

2. $20\mathrm{g}$ of carbon and $5\mathrm{g}$ of hydrogen

3. $22\mathrm{g}$ of carbon and $3\mathrm{g}$ of hydrogen

4. $24\mathrm{g}$ of carbon and $1\mathrm{g}$ of hydrogen

Q.

What is the atomic mass of water? How is this determined?

Q.

The mass ratio of Carbon to Hydrogen in Methane $C{H}_4$ is 3:1. How much amount of hydrogen is required to react with 36 gms of carbon to form methane?

1. 30 gm

2. 10 gm

3. 12 gm

4. 16 gm

Q. 1 u or 1 amu means

1. Mass of C-12 atom

2. $\frac{1}{12}$th mass of an atom of C-12 atom

3. Mass of O-16 atom

4. Mass of Hydrogen molecule

Q.

The mass of one helium atom is

1. $2\mathrm{amu}$

2. $3\mathrm{amu}$

3. $4\mathrm{amu}$

4. $8\mathrm{amu}$

Q. One atomic mass unit is $\frac{1}{12}$ times the mass of one atom of .

1. carbon-12
2. nitrogen-12
3. boron-12

Q.

The mass of an electron is about 1/2000 times that of a hydrogen atom.

1. True
2. False

Q.

Ordinary chlorine has two isotopes ${}_{17}{}^{35}Cl$ and ${}_{17}{}^{37}\mathrm{Cl}$ in the ratio $3:1$. Calculate the relative atomic mass (atomic weight) of chlorine.

Q.

Give the number of protons in 1.$\mathrm{Cl}$

Q. 12 dalton equals $(\frac{1}{12}{)}^{\text{th}}$ the weight of an atom of carbon 12.

1. True
2. Flase

Q.

A balloon is filled with 15.5 g of water. What will be the number of water molecules contained in the balloon?

1. $4.18\times {10}^{23}$
2. $2.54\times {10}^{23}$
3. $5.18\times {10}^{23}$
4. $3.28\times {10}^{23}$

Q. What are isotopes?

Q. The mass of an electron is less than that of a atom.

1. hydrogen
2. sodium
3. carbon

Q.

Find the mass of oxygen contained in 1 kg of Potassium nitrate (KNO₃)

1. 475.5 g
2. 485.5 g
3. 475.2 g
4. 485.2 g

Q.

The mass of Sodium in 11.7 g of Sodium chloride is

1. 6.9 g
2. 7.1 g
3. 2.3 g
4. 5.02 g

Q. If the mass of a single atom of an element is $5.31\times {10}^{-23}$ g, then which amongst the following elements could it be?

1. Oxygen
2. Potassium
3. Sulphur
4. Nitrogen

Q.

One atomic mass unit is _______ of the mass of one atom of _________ isotope.

1. , Carbon-14

2. , Hydrogen

3. , Carbon-12

4. , Sulphur

Q.

What does the abbreviation amu stand for?

1. Atomic molecular unit

2. Atomic mass unit

3. Atomic mole unit

4. Atomic measuring unit

Q. The formula unit mass of ${\text{MgCl}}_2$ is _____.

1. 97 u
2. 95 u
3. 94.5 u
4. 96.5 u

Q.

What does the abbreviation 'amu' stand for?

1. american money unit

2. atomic mass unit

3. atomic mole unit

4. atomic measuring unit

Q. One atomic mass unit is exactly equal to __________ of the mass of one atom of carbon-12.

1. 1/14
2. 1/12
3. 1/10
4. 1/8

Q. The sum of the atomic masses of all the atoms in a molecule of the substance is known as:

1. molecular structure
2. molecular composition
3. molecular density
4. molecular mass

Q.

The atomic mass of Oxygen is 16 u.

Considering the above statement, which among the following options can be inferred?

1. The mass is with respect to Carbon -12 atom.

2. The atomic mass of Oxygen is 16 of the mass of carbon 12 atom.

3. The mass is with respect to Carbon -12 atom and the atomic mass of Oxygen is 16 of the mass of carbon 12 atom.

4. The atomic mass of hydrogen is 16 times the mass of Hydrogen.

Q. Element after atomic number $92$ are called :

1. inner-transition elements
2. lanthanoids
3. transuranium elements
4. actionoids

Q.

what does u. stand for in chemistry?

Q.

The unit of --------- is u.

Q. State the number of atoms of each element present in:

1. C6H12O6
2. H2SO4
3. HNO3
4. CaCO3