1) All of the following are oxidation-reduction reactions except
(a) 2Al(s) + Fe2O3(s) �¨A12O3(s) + 2Fe(s)
(b) (NH4)2Cr2O7(s) �¨ Cr2O3(s) + N2(g) + H2O(1)
(c) Cu(s) + 2H2SO4(aq) �¨ CuSO4(aq) + SO2(g) + 2H2O(1)
(d) Hg(NO3)2 + 4KI �¨ K2HgI4(aq) +
2 KNO3(aq)
(e) 2Na(s) + 2H2O(1) �¨ 2NaOH(aq) +
H2(g)
2) 13.00 mL of 0.52 M barium chloride is added to 8.00 mL of 0.68 M sodium sulfate in a beaker.
Identify the limiting reagent and its concentration?
BaCl2(aq) + Na2SO4(aq) ---> BaSO4 (s) + 2NaCl(aq)
(a) BaCl2 is the limiting reagent at a concentration of 6.76 x 10-3 mol
(b) BaCl2 is the limiting reagent at a concentration of 5.44 x 10-3 mol
(c) Na2SO4 is the limiting reagent at a concentration of 5.44 x 10-3 mol
(d) Na2SO4 is the limiting reagent at a concentration of 6.76 x 10-3 mol
(e) Neither as both have the same concentration
iii) Dilute acetic acid is added to solid nickel(II) carbonate.
i am not sure with the question , if u explain how to work out
Determine moles BaCl2 = M x L.
Determine moles Na2SO4 = M x L.
If moles are different e can't be right. Determine the lesser quantity, that will be the limiting reagent. I should point out here that none of the answers, technically, is correct. All of the answers cite moles while concn is moles/L. I supppose you are to go with the answer that is correct in moles.
iii. I don't know what the question is for this one but NiCO3 will dissolve in dilute acetic acid if it isn't too dilute.
it is to work to find the net ionic equation for question iii
Sure, I can explain how to work out the answers to the questions:
1) To determine which of the given reactions are oxidation-reduction reactions, you need to identify the changes in oxidation states of the elements involved. In an oxidation-reduction reaction, there will be a transfer of electrons between the reactants.
(a) In this reaction, aluminum (Al) is oxidized from an oxidation state of 0 to +3, while iron (Fe) is reduced from an oxidation state of +3 to 0. Therefore, this reaction is an oxidation-reduction reaction.
(b) In this reaction, chromium (Cr) is reduced from an oxidation state of +6 to +3 and nitrogen (N) is oxidized from -3 to 0. This is also an oxidation-reduction reaction.
(c) In this reaction, copper (Cu) is oxidized from an oxidation state of 0 to +2, while sulfur (S) is reduced from an oxidation state of +6 to +4. So, this is an oxidation-reduction reaction.
(d) In this reaction, there is no change in the oxidation states of the elements. It is a precipitation reaction, not an oxidation-reduction reaction.
(e) In this reaction, sodium (Na) is oxidized from an oxidation state of 0 to +1, while hydrogen (H) is reduced from an oxidation state of +1 to 0. This is an oxidation-reduction reaction.
Therefore, the correct answer is (d) Hg(NO3)2 + 4KI ➡ K2HgI4(aq) + 2KNO3(aq) as it is not an oxidation-reduction reaction.
2) To identify the limiting reagent and its concentration, you need to determine the number of moles of each reactant. The reactant that produces the smaller amount of product is the limiting reagent.
First, calculate the number of moles of BaCl2:
moles of BaCl2 = volume (in L) × concentration (in M) = (13.00/1000) × 0.52 = 0.00676 mol
Next, calculate the number of moles of Na2SO4:
moles of Na2SO4 = volume (in L) × concentration (in M) = (8.00/1000) × 0.68 = 0.00544 mol
From the balanced equation, you can see that the ratio of moles of BaCl2 to moles of BaSO4 is 1:1. Therefore, the limiting reagent is the one that produces the smaller number of moles of BaSO4, which is Na2SO4.
Hence, the correct answer is (c) Na2SO4 is the limiting reagent at a concentration of 5.44 x 10-3 mol.
iii) To dilute acetic acid (CH3COOH) with solid nickel(II) carbonate (NiCO3), you would need to first calculate the number of moles of acetic acid and the number of moles of solid nickel(II) carbonate.
To calculate the number of moles of acetic acid, you would use the formula: moles = volume (in L) × concentration (in M).
To calculate the number of moles of solid nickel(II) carbonate, you would use the formula: moles = mass (in g) / molar mass (in g/mol).
You would need to provide additional information such as the volume of acetic acid and the mass of solid nickel(II) carbonate to calculate the exact values.