Answer:
0.043 M
Explanation:
The reaction that takes place is:
- Ca(OH)₂ + 2HCl → CaCl₂ + 2H₂O
First we <u>calculate how many HCl moles reacted</u>, using the <em>given concentration and volume required to reach the equivalence point</em>:
- 0.029 M HCl * 37.3 mL = 1.0817 mmol HCl = 1.0817 mmol H⁺
As 1 mol of H⁺ reacts with 1 mol of OH⁻, in the 25.0 mL of the Ca(OH)₂ sample there are 1.0817 mmoles of OH⁻.
With that in mind we can <u>calculate the hydroxide ion concentration in the original sample solution</u>, using <em>the calculated number of moles and given volume</em>:
- 1.0817 mmol OH⁻ / 25.0 mL = 0.043 M
Answer:
The correct answer is - B. dissolving → evaporation filtration → crystallisation
Explanation:
The method of the preparation of a pure sample of copper(II) sulfate from dilute sulfuric acid and copper II oxide is given as follows:
step 1. Adding dilute sulfuric acid into a beaker. Using bunsen burner heat the beaker.
step 2. Adding the copper (II) oxide into the beaker and give it a little time at a time to the warm dilute sulfuric acid and stir
step 3. Filtering the mixture into an evaporating vessel to remove the excess copper (II) oxide and water from the filtrate.
Step 4. leave the rest filtrate to crystallize.
Copper (II) Oxide {CuO (s)} + Dilute Sulfuric Acid {H2SO4 (aq)} → Copper (II) Sulphate {CuSO4 (s)} + Water {H2O}
Answer:
4 & 5 have the same number of elements
I think the correct answer would be HCl + NaHCO3 -> NaCl + H2O + CO2, 2HCl + CaCO3 -> CaCl2 + CO2 + H2O, 2HCl + Mg(OH)2 -> MgCl2 + 2H2O. Hydrochloic acid would react with the basic substances in the stomach which are magnesium hydroxide, sodium bicarbonate and <span>calcium carbonate.</span>
