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**Problem**: Baking soda (sodium bicarbonate, NaHCO3) reacts with acids
in foods to form carbonic acid (H2CO3), which in turn decomposes to water and carbon dioxide gas. In a cake batter, the CO2(g) forms bubbles and causes the cake to rise.The density of baking soda is 2.16 g/cm3. Calculate the concentration of lactic acid in one cup of sour milk (assuming the rule of thumb applies), in units of mol/L. (One cup = 236.6 mL = 48 teaspoons).

###### FREE Expert Solution

We are asked to calculate the concentration of lactic acid in one cup of sour milk (assuming the rule of thumb applies), in units of mol/L.

**The rule of thumb in baking is that 1/2 teaspoon of baking soda is neutralized by one cup of sour milk. **

Recall that ** molarity** is the ratio of the moles of solute and the volume of solution (in liters). In other words:

$\overline{){\mathbf{Molarity}}{\mathbf{}}{\mathbf{\left(}}{\mathbf{M}}{\mathbf{\right)}}{\mathbf{=}}\frac{\mathbf{moles}\mathbf{}\mathbf{solute}\mathbf{}\mathbf{\left(}\mathbf{mol}\mathbf{\right)}}{\mathbf{liters}\mathbf{}\mathbf{of}\mathbf{}\mathbf{solution}\mathbf{}\mathbf{\left(}\mathbf{L}\mathbf{\right)}}}$

We’re given the density of baking soda is 2.16 g/cm^{3}. Recall that ** density** is given by:

$\overline{){\mathbf{density}}{\mathbf{=}}\frac{\mathbf{mass}}{\mathbf{volume}}}$

**The steps we need to do for this solution are:**

*Step 1:* Convert teaspoon (tsp) to cubic centimeters (cm^{3}) and 1 cup to liters (L).

*Step 2:* Calculate the moles of baking soda (sodium bicarbonate, NaHCO_{3})

*Step 3:* Perform a mole-to-mole comparison between lactic acid and sodium carbonate (1 mol lactic acid:1 mol sodium carbonate).

*Step 4:* Calculate the molarity of the solution.

###### Problem Details

Baking soda (sodium bicarbonate, NaHCO_{3}) reacts with acids
in foods to form carbonic acid (H_{2}CO_{3}), which in turn decomposes to water and carbon dioxide gas. In a cake batter, the CO_{2}(g) forms bubbles and causes the cake to rise.

The density of baking soda is 2.16 g/cm^{3}. Calculate the concentration of lactic acid in one cup of sour milk (assuming the rule of thumb applies), in units of mol/L. (One cup = 236.6 mL = 48 teaspoons).

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Our tutors have indicated that to solve this problem you will need to apply the Calculate Molarity concept. You can view video lessons to learn Calculate Molarity Or if you need more Calculate Molarity practice, you can also practice Calculate Molarity practice problems .