Answer:
0.00642mole
Explanation:
Molar Mass of Cu = 63.5g/mol
Mass of Cu from the question = 0.4076g
Number of mole =?
Number of mole = Mass /Molar Mass
Number of mole of Cu = 0.4076/63.5 = 0.00642mole
Less than 5cm of precipitation a year
Answer:If we dissolve NaF in water, we get the following equilibrium:
text{F}^-(aq)+text{H}_2text{O}(l) rightleftarrows text{HF}(aq)+text{OH}^-(aq)
The pH of the resulting solution can be determined if the K_b of the fluoride ion is known.
20.0 g of sodium fluoride is dissolve in enough water to make 500.0 mL of solution. Calculate the pH of the solution. The K_b of the fluoride ion is 1.4 × 10 −11 .
Step 1: List the known values and plan the problem.
Known
mass NaF = 20.0 g
molar mass NaF = 41.99 g/mol
volume solution = 0.500 L
K_b of F – = 1.4 × 10 −11
Unknown
pH of solution = ?
The molarity of the F − solution can be calculated from the mass, molar mass, and solution volume. Since NaF completely dissociates, the molarity of the NaF is equal to the molarity of the F − ion. An ICE Table (below) can be used to calculate the concentration of OH − produced and then the pH of the solution.
Explanation:
The density of the carbon tetrachloride is 1.59 g/mL.
Mass of CCl₄ = 703.55 g – 345.8 g = 357.75 g
Density = mass/volume = 357.75 g/225 mL = 1.59 g/mL
