In an experiment to find the percentage of calcium carbonate in sand from a beach, 1.86 g of sand reacted with an excess of dilute hydrochloric acid to give 0.55 g of carbon dioxide.

CaCO3 (s) + 2HCL (aq) – CaCl2(aq) + CO2(g) + H2O (l)

1.Calculate the number of moles of carbon present in 0.55 g of CO2

2.How many moles of calcium carbonate must have been present in the sand to produce this amount of carbon dioxide?

3. Calculate the mass of calcium carbonate present in the sand.

4. Calculate the percentage of calcium carbonate present in the sand.

Note to reader:
the questions i really find difficult is 2 and 3.

What is the molarity of a solution containing 8 grams of solute in 500 mL of solution? Round to the nearest hundredth. Don't forget the units! (gram formula mass of solute = 24 g)

To solve questions 2 and 3, we will follow these steps:

Step 1: Calculate the number of moles of carbon in CO2.
Step 2: Use the balanced equation to find the number of moles of calcium carbonate that produced this amount of CO2.
Step 3: Calculate the mass of calcium carbonate using the molar mass.
Step 4: Calculate the percentage of calcium carbonate in the sand.

Now let's go through each step in detail:

1. Calculate the number of moles of carbon present in 0.55 g of CO2:
To find the number of moles of carbon, we need to use the molar mass of carbon dioxide (CO2). The molar mass of carbon dioxide is 44 g/mol.

Moles of Carbon = Mass of CO2 / Molar mass of CO2
Moles of Carbon = 0.55 g / 44 g/mol

2. How many moles of calcium carbonate must have been present in the sand to produce this amount of carbon dioxide?
According to the balanced equation, 1 mole of calcium carbonate (CaCO3) produces 1 mole of carbon dioxide (CO2).

Therefore, the number of moles of calcium carbonate is equal to the number of moles of carbon dioxide.

Number of moles of calcium carbonate = Moles of Carbon Dioxide from step 1

3. Calculate the mass of calcium carbonate present in the sand:
To calculate the mass of calcium carbonate, we need to use the number of moles of calcium carbonate from step 2 and the molar mass of calcium carbonate (100.09 g/mol).

Mass of Calcium Carbonate = Number of moles of calcium carbonate × Molar mass of calcium carbonate

4. Calculate the percentage of calcium carbonate present in the sand:
To calculate the percentage, we divide the mass of calcium carbonate by the mass of the original sand and multiply by 100.

Percentage of Calcium Carbonate = (Mass of Calcium Carbonate / Mass of Sand) × 100

Note: The mass of sand is not given in the question, so we are unable to calculate the exact percentage. You would need to provide the mass of the original sand.

I hope this explanation helps you understand the steps required to solve these questions.

2) YOur balanced equation gives the answer: 1 mole of calcium carbonate yields one mole of carbon dioxide, which is 12 grams carbon. So for .55grams, you must have had .55/12 moles of calcium carbonate.

3. knowing the moles of calcium carbonate, change it to mass (grams).

0.56