Answer:
(c) only Ca2+(aq) and Hg2+(aq)
Explanation:
- In the first step, hydrochloric acid (HCl) is added to the solution. In this case the equilibrium that could take place is:
Ag⁺(aq) + Cl⁻(aq) ↔ AgCl(s)
But no precipitate was formed, so Ag⁺(aq) is absent.
- By adding H₂SO₄(aq) the next equilibrium that could take place is:
Ca⁺²(aq) + SO₄⁻²(aq) ↔ CaSO₄(s)
A white precipitate was formed, so Ca⁺² is present in the solution.
- The following could take place after adding H₂S(aq):
Hg²⁺(aq) + S⁻² ↔ HgS(s)
A black precipitate formed, so Hg⁺² is present as well.
Answer:
paramagnetic
Explanation:
The complex ion is : [Cr(CN)₆]³⁻
Oxidation state of Cr in [Cr(CN)₆]³⁻ is:
x + (-1)6 = -3
x = +3
CN⁻ is a strong field ligand which can result in pairing of the electrons.
The electronic configuration of Cr is:
1s²2s²2p⁶3s²3p⁶3d⁵4s¹
The electronic configuration of Cr³⁺ is:
1s²2s²2p⁶3s²3p⁶3d³
<u>These 3 electrons will be singly present in the 3 degenerate t₂g orbitals and per Hund's rule, pairing will not occur in the same level energy orbitals. So , no. of unpaired electrons will be 3 and the complex will be paramagnetic.</u>
Answer: 0.72 litres of water is wasted in one day.
Explanation:
First you need to find out how many minutes are in a day. Do this by multiplying the number of minutes in an hour (60) by the number of hours in a day (24). 24 x 60 = 1440. If the faucet is dripping at 5 drops per minute, then multiply 5 by the number of minutes in a day (1440) to see how many drops drip in one day. 5 x 1440 = 7200. Now we need to figure out how many mL fo water that is. if 10 drops is 1 mL, then we need to divide the total number of drops (7200) by 10. 7200 divided by 10 is 720. That means 720 mL of water is dripping per day. Finally, we must convert mL to litres. There are 1000 mL in one litre, so divide 720 by 1000. The final answer is 0.72
