Calculations problems in AC chapter 1-4

What is the molarity of Na⁺ if 0.5 moles of Na₂CO₃ when it is dissolved in 500 ml of water. (Write your answer without the unit given that the unit is in moldm^-3)

What is the molarity of K₂CO₃ if 0.5 moles of K₂CO₃ when it is dissolved in 500 ml of water. (Write your answer without the unit given that the unit is in moldm^-3)

What is the molarity of C₆H₁₂O₆ if 0.5 moles of C₆H₁₂O₆ when it is dissolved in 250 ml of water. (Write your answer without the unit given that the unit is in moldm^-3)

What is the mass of sodium ions in 50g of bottled water that contains 67 ppb of NaCl? (Write your answer without the unit given that the unit is in g)

• 3.35x10^-6

• 3.35x10⁶

• 1.34x10⁹

• 7.46x10^-10

What is the mass of chlorine ions in 50g of bottled water that contains 67 ppb of CaCl₂? (Write your answer without the unit given that the unit is in g)

• 3.35x10^-6

• 3.35x10⁶

• 1.34x10⁹

• 7.46x10^-10

• 6.7x10^-6

What is the standard deviation of the following numbers to the nearest 3 sig fig.

0.5, 0.6, 0.9, 0.4

What is the pH of a solution of ethanoic acid that is in equilibrium containing 1 moldm^-3 of ethanoic acid, 0.5 moldm^-3 of sodium ethanoate and a K_a value of 1.8 x10^-5 moldm^-3. Give your answer to the nearest 4sig fig.

What is the number of moles of oxygen that is required to fully react with 3 moles of butanol (C₄H₉OH) to form carbon dioxide and water. (Write our answer to the nearest 1 decimal place)

What is the mass of ammonia that will be produced from the reaction of 1.2044x10²⁴ nitrogen molecules with excess of hydrogen, assuming it is a complete reaction, (Avogadro's constant is 6.022x10²³) (Write your answer without the unit given that the unit is in g)