Calculating Molarity and Mass

This video tutorial from JD Science Prep covers the calculation of concentration using the formula C = n/V, where C is concentration, n is moles, and V is volume. The video includes three examples: calculating the molarity of a sodium hydroxide solution, determining the amount of water needed for a potassium chloride solution, and calculating the mass of calcium oxide required for a solution. Each example involves converting between grams and moles, using molar mass, and applying significant figures.

What does the formula C = n/V represent in chemistry?

• Concentration equals mass over volume

• Concentration equals moles over mass

• Concentration equals volume over moles

• Concentration equals moles over volume

In the formula C = n/V, what does 'n' stand for?

• Concentration

• Volume

• Mass

• Moles

How do you convert grams to moles for a substance?

• Add the molar mass

• Subtract the molar mass

• Divide by the molar mass

• Multiply by the molar mass

What is the molarity of a solution if 11.5 g of NaOH is dissolved in 245 mL of water?

• 1.17 M

• 0.75 M

• 0.50 M

• 2.45 M

What is the first step in calculating the volume of water needed for a solution?

• Determine the desired molarity

• Convert grams to moles

• Find the mass of the solute

• Calculate the molar mass

How many liters of water are needed to make a 1.2 M solution with 13 g of KCl?

• 0.15 L

• 0.25 L

• 0.35 L

• 0.45 L

What is the molar mass of potassium chloride (KCl) used in the calculations?

• 40.00 g/mol

• 74.55 g/mol

• 58.44 g/mol

• 56.08 g/mol

What is the concentration of a solution if 0.328 moles of CaO are dissolved in 0.41 L of water?

• 1.20 M

• 0.50 M

• 0.80 M

• 0.90 M

How do you convert moles to grams for a substance?

• Subtract the molar mass

• Add the molar mass

• Divide by the molar mass

• Multiply by the molar mass

What mass of calcium oxide is needed to make a 0.80 M solution in 410 mL of water?

• 18 g

• 25 g

• 30 g

• 15 g