Calculating Percent Yield

1.Sn(IV)4? -my experimental value was 0.194g and my melting point: 147 C - my balanced equation Sn + 2I2 -------> SnI4 - we used .24g of Sn, 0.95g I2 (I got 1.25 g as my theoretical value didn't look right so I need to double check) 2.Sn(II)I2? -my experimental value was 0.314g and melting point 160 C - balanced equa ...continues

Cu-64

Write equation decomposition Cu-64 by beta decay?

Rates of radioactive decay

(1) A one- milligram sample of Cu-64 (nuclear mass =63.92 amu) has an activity of 3.82*10^3 Ci i) How many atoms are in the sample? ii) what is the decay rate in atoms/s? iii) what is the rate constant in min-1? iv) what is the half-life in minutes? 2)what percentage of Cu-64 will decay in 4.00hr?

Precipitating and Dissolving Zinc Hydroxide

Hello: 1) I have zinc hydroxide in solution --- Zn(OH)2 is generally insoluble 2) My goal is to first render the zinc completely insoluble 3) We are given a choice of Al2(SO4)3 or H2SO4 in order to lower the pH and solubilize the zinc ---- which is better and why? 4) Then, at a later time, my goal is to render the zi ...continues

Mixture of Weak Acids and pH

Nitrous acid, HNO2, and butyric acid, HC4H7O2, are both weak monoprotic acids. Their pKa values (at 25oC) are 3.14 and 4.82, respectively. What is [C4H7O2-] in a solution in which the stoichiometric concentrations of HNO2 and HC4H7O2 are 0.113 mol/L and 1.51x10-6 mol/L, respectively? Hints: 1. The stoichiometric concentr ...continues

Acids and Bases : Neutralization Reaction

If 64.0 mL of 0.133 mol/L NaOH(aq) and 35.0 mL of 0.185 mol/L HA(aq) are mixed, then what is [HA] at equilibrium? Assume that HA is a weak monoprotic acid with pKa=5.23 at 25oC. Give your answer with three significant figures.

Neutralization and pH

How many moles of NaOH must be added to 0.400 L of 0.177 mol/L HC3H5O2(aq) to obtain a solution with pH=4.7? Assume the temperature is 25C. (For HC3H5O2, pKa=4.89 at 25C). Give your answer accurate to three significant figures

pH and Neutralization

What is the final pH of the solution when 5.00 mL of 0.119 mol/L NaOH(aq) and 25.0 mL of 0.189 mol/L HNO2(aq) are mixed? Assume the temperature is 25C. (For HNO2, pKa=3.14 at 25C) Give your answer accurate to two decimal places.

What is the pH at equivalence point?

What is the pH at the equivalence point when when 25.0 mL of 0.175 mol/L HNO2(aq) is titrated with 0.137 mol/L NaOH(aq)? Assume the temperature is 25C. (For HNO2, pKa=3.14 at 25C). Give your answer accurate to two decimal places.

Neutrlization and Weak Monoprotic Acids

If 92.0 mL of 0.129 mol/L NaOH(aq) and 50.0 mL of 0.185 mol/L HA(aq) are mixed, then what is [HA] at equilibrium? Assume that HA is a weak monoprotic acid with pKa=5.83 at 25C. Give your answer with three significant figures.