Answer:
\large \boxed{\text{12.3 mol HCl}}
Explanation:
We need a balanced chemical equation with moles.
2HCl +Ca(OH)₂ ⟶ CaCl₂ + 2H₂O
n/mol: 12.3
The molar ratio is 2 mol H₂O:2 mol HCl.

Answer:
The percentage efficiency of the electrical element is approximately 82.186%
Explanation:
The given parameters are;
The thermal energy provided by the stove element,
= 3.34 × 10³ J
The amount thermal energy gained by the kettle,
= 5.95 × 10² J
The percentage efficiency of the electrical element in heating the kettle of water, η%, is given as follows;

Therefore, we get;

The percentage efficiency of the electrical element, η% ≈ 82.186%.
Answer:
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s
Explanation:
You can predict the order of orbital energies by constructing a diagram as shown below.
Follow the arrows to get the orbitals in order of increasing energy.
The order is
1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s