Question

How many moles of sodium chloride are present in a sample that has a mass of 1.17g?
(A) 0.005mol
(B) 0.01mol
(C) 0.02mol
(D) 0.03mol

Answer 1

For calculating the number of moles, we can use the formula of the number of moles expressed as.
The number of moles = given mass /molar mass.

Complete step by step solution:
We have been provided with 1.17g of sodium chloride,
Sodium chloride has a formula: NaCl,
Sodium chloride, commonly known as salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions.
So, we need to calculate the moles of 1.17g of sodium chloride,
The mole is the unit of measurement for the amount of substance in the International System of Units. A mole of a substance or a mole of particles is defined as exactly $6.02214076\times {{10} ^ {23}}$ particles, which may be atoms, molecules, ions, or electrons. In short, for particles $1mol=6.02214076\times {{10} ^ {23}}$
For calculating moles,
We know the molar mass of NaCl,
Molar mass of sodium (Na) = 23,
Molar mass of chlorine (Cl) = 35.5,
So, the molar mass of NaCl= 23+35.5= 58.5g,
Now we will be calculating the number of moles,
Given the mass of sodium chloride: 1.17g
The molar mass of sodium chloride: 58.5g
Number of moles= given mass / molar mass,
So, the number of sodium chloride: $n=\dfrac {1.17} {58.5}$
Simplifying the above equation, we would get: $n=0.02moles$,
So, we can say that the number of moles associated with 1.17g sodium chloride is 0.02moles.

Therefore, we can conclude that option (C) is correct.

Note: Sodium chloride is also known as salt. It is an essential compound our body uses to: absorb and transport nutrients. maintain blood pressure. maintain the right balance of fluid.