Answer: I did the research myself since I couldn’t find the answers.
Physical change:
Wax melting from applied heat
Grinding wheat to make flour
Adding copper with gold to make jewelry
Chemical Reaction:
Growth of a seed into a seedling
Making caramel by burning sugar
Tarnishing of silver
Explanation:
Thanks google
Q1. TI (210/81Thallium)
Q2.
The answers are opposite from each other
The heat used in phase changes is calculated by multiplying the mass of the substance by the energy of the phase change. In this case, for liquid to boil, we would find total heat by multiply the mass of liquid by the latent heat of vaporization (Hvap). If we are instead given the Hvap and the total heat of 1 kJ, we would divide 1 kJ by the Hvap (which is usually in kJ/kg) to get the mass of liquid boiled (in kg).
Answer:
1. NaOH + H₂O → Na⁺ + OH⁻ + H₂O + heat
2. NaOH + HCl → NaCl + H₂O
Explanation:
1. The dissolving of NaOH in water is an exothermic reaction resulting a heat. It also causes the dissociation of NaOH to its ions (Na⁺ and OH⁻).
So, the balanced equation will be NaOH + H₂O → Na⁺ + OH⁻ + H₂O + heat.
2. The reaction between acid and base resulting salt and water. It is considered as a neutralization reaction.
The reaction between HCl and NaOH will give sodium chloride and water and the balanced equation will be NaOH + HCl → NaCl + H₂O.
