(1) To make NaTcO4, Tc metal is dissolved in nitric acid to make HTcO4, NO2 and H2O. Then the product HTcO4 is treated with NaOH to make NaTcO4. If you begin with 4.5 mg of Tc metal, how much of NaOH (in grams) is required to convert all of the HTcO4 into NaTcO4?
Tc + 7HNO3 = HTcO4 + 7NO2 + 3H2O
HTcO4 + NaOH = NaTcO4 + H2O
I used these to find the answer.... 0018 g NaOH.
(2)Explain how to prepare zinc chloride by a) acid-base reaction or b) a gas formation reaction. The starting materials available are ZnCO3, HCL, CL2, HNO3, NaCL, Zn(NO3)2, and Zn.
(a) ZnCO3(aq) + 2HCl(aq) ---> ZnCl2(aq) + H2O(l) + CO2(g); ZnCO3 is a base, HCl is an acid.
(b)Zn + HCl --> ZnCl2 + H2; H2 is a gas
Answered below.
To find the answer to the first question, you can follow these steps:
1. Start with the given chemical equation: HTcO4 + NaOH = NaTcO4 + H2O.
2. Determine the molar mass of Tc by finding its atomic mass from the periodic table. Tc has an atomic mass of 98 g/mol.
3. Convert the mass of Tc metal into moles by using the formula: moles = mass / molar mass. In this case, moles = 4.5 mg / (98 g/mol x 1000 mg/g) = 0.000046 moles.
4. Use stoichiometry to find the moles of NaOH required. From the balanced equation, you can see that one mole of HTcO4 reacts with one mole of NaOH. Therefore, the moles of NaOH required will also be 0.000046 moles.
5. Find the molar mass of NaOH, which is 40 g/mol.
6. Convert the moles of NaOH into grams by using the formula: mass = moles x molar mass. In this case, mass = 0.000046 mol x 40 g/mol = 0.0018 g.
So, the amount of NaOH required to convert all of the HTcO4 into NaTcO4 is 0.0018 grams.
For the second question, there are two possible methods to prepare zinc chloride:
(a) Acid-base reaction:
- Based on the given equation: ZnCO3(aq) + 2HCl(aq) ---> ZnCl2(aq) + H2O(l) + CO2(g).
- Start with the available ZnCO3 (zinc carbonate) and HCl (hydrochloric acid).
- Mix them together in the appropriate ratios according to the balanced equation and perform the reaction.
- The resulting products will be zinc chloride (ZnCl2), water (H2O), and carbon dioxide (CO2).
(b) Gas formation reaction:
- Based on the given equation: Zn + HCl --> ZnCl2 + H2.
- Start with the available Zn (zinc) and HCl (hydrochloric acid).
- Combine them in the appropriate ratios according to the balanced equation and carry out the reaction.
- The resulting products will be zinc chloride (ZnCl2) and hydrogen gas (H2).
By following these steps and utilizing the provided starting materials, you can prepare zinc chloride using either an acid-base reaction or a gas formation reaction.