Answer:
Explanation:
Chemically, we can have a reaction between chlorine gas and solid sodium
This reaction is actually explosive and would produce fine powder of sodium chloride
We have the reaction as follows:

Essentally, what we can deduce from here is that we do not need to add water to the flask. Except for the reason that we would want the sodium chloride solid in the solution form, there is absolutely no reason to add water to the flask as the reaction would proceed normally
Answer:
Because it has a quickly sedative effect and it has antimicrobial effect.
Explanation:
This gas is useful because is used to trait pain, reduce anxiety and promote relaxation, slow down the body reaction, so the dentist can use it to calm down the patients.
If the patient present some injuries, this gas can help in wound healing.
The reaction of acid, assuming HCl and calcium carbonate always produces a gas. The reaction is as follows:
2 HCl + CaCO3 --> CaCl2 + H2CO3
H2CO3, carbonic acid, is a weak acid that is unstable in water solutions at high concentrations. As such, it decomposes:
H2CO3 --> H2O + CO2
Then,
2 HCl + CaCO3 --> CaCl2 + H2O + CO2
The total ionic equation looks as follows:
2H+(aq) + 2 Cl-(aq) + CaCO3(s) --> Ca+2(aq) + 2 Cl-(aq) + H2O(l) + CO2(g)
Clearly, Cl- is a spectator ion as it is unchanged in the reaction. The net ionic reaction looks as follows:
2 H+(aq) + CaCO3(s) --> Ca+2(aq) + H2O(l) + CO2(g)
Answer: Water becomes gas at D-E.
Explanation:
In the flat line D-E water is absorbing energy to become gas, and when the water is completely gas, the temperature will increase again therefore the line will rise up.
Answer: C. High surface tension
Explanation:
Water has high specific heat as it require high heat to raise the temperature of 1 g of water through
.
Surface tension is the net downward force acting on the surface of liquids due to the cohesive nature of liquids.
Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom making it polar. Thus water molecules present on the surface are strongly attracted by the molecules present below the surface and thus act as a stretched membrane.
The surface acquires a minimum surface are and thus acquire a spherical shape.