Animated Solution for Chemistry - Basic Concepts in Chemistry: If the concentration of glucose (${\text{C}}_6{\text{H}}_{12}{\text{O}}_6$) in blood is $0.72{\text{ gL}}^{-1}$, the molarity of glucose in blood is ...... $\times 10^{-3}\text{ M}$. (Nearest integer) [Given : Atomic mass of $\text{C}=12$, $\text{H}=1$, $\text{O}=16\text{ u}$]

Imagine you are looking at a medical report, and it states the concentration of glucose in a blood sample is $0.72\text{ g/L}$. What does this actually mean?

It tells us that in every one liter of blood, there is exactly $0.72\text{ grams}$ of glucose dissolved in it. However, in chemistry, we rarely talk in terms of pure mass when discussing reactions or concentrations. We prefer to talk in terms of moles, which represents the actual count of molecules.

Our goal is to convert this mass-based concentration into Molarity, which is the number of moles of solute per liter of solution.

To bridge the gap between grams and moles, we need a conversion factor. That factor is the Molar Mass.

The formula for Molarity ($M$) when given the concentration in $\text{g/L}$ is beautifully simple:

Before we can use this equation, we need to find the molar mass of our solute, glucose.

Glucose has the chemical formula ${\text{C}}_6{\text{H}}_{12}{\text{O}}_6$. To find its molar mass, we sum the atomic masses of all its constituent atoms.

We are given the atomic masses: Carbon is $12\text{ u}$, Hydrogen is $1\text{ u}$, and Oxygen is $16\text{ u}$.

This means one mole of glucose weighs exactly $180\text{ grams}$.

Now, we have everything we need. Let's substitute our values into the master equation.

To make the calculation easier, you can think of $0.72$ as $72\times 10^{-2}$.

Dividing $72$ by $180$ gives $0.4$.

The question asks us to format our answer as an integer multiplied by $10^{-3}$.

Comparing this to the requested format of $x\times 10^{-3}\text{ M}$, we can clearly see that our integer value is $4$.