Question

how many moles are there in 17.5 grams of sodium?
a 0.761
b 22.99
c 1.05×10²⁵
d 1.31

Explanation:

Step1: Recall the formula for moles

The formula for calculating the number of moles \(n\) is \(n=\frac{m}{M}\), where \(m\) is the mass and \(M\) is the molar mass.

Step2: Identify the molar mass of sodium

The molar mass \(M\) of sodium (\(Na\)) is \(22.99\space g/mol\). The mass \(m = 17.5\space g\).

Step3: Calculate the number of moles

Substitute the values into the formula: \(n=\frac{17.5\space g}{22.99\space g/mol}\approx0.761\space mol\)

Answer:

A. 0.761