Answer: NaCl is an ionic compound
Explanation: Sodium Chloride is formed from Na+ and Cl- ions.
It is soluble in water, it has crystalline structure, it has high melting point and
It is insulator as solid form. Water solution leads current.
Answer:
The concentration and pKa of an acid and its conjugate base can limit the buffering capacity of a molecule.
Explanation:
A buffer is an acid and its conjugate base and the quality of it depends on its buffer capacity. This buffer capacity is the resistance to change the pH of the solution when strong acids or bases are added. The buffer capacity is related to the buffer concentration, the concentration of the acid end its conjugate base. Also, every acid has a pKa and the buffer capacity is at its maximum at the pKa value and can buffer the solution between ± 1 the pKa value.
Answer: a) 
b) 
Explanation: Visible light is a form of electromagnetic wave.
Wavelength is defined as the distance between two successive crests of a wave. It is represented as symbol
.
Frequency is defined as the number of complete cycles happening per second. It is represented by the symbol
.
Wavelength and Frequency follow inverse relation,

where, c = speed of light = 
Wavelength and frequency of a wave is usually expressed in a range.
a) 
b) 
Answer:
Electrolysis of water is the process of using electricity to decompose water into oxygen and hydrogen gas. Hydrogen gas released in this way can be used as hydrogen fuel, or remixed with the oxygen to create oxyhydrogen gas, which is used in welding and other applications.Ordinarily, the freezing point of water and melting point is 0 °C or 32 °F. The temperature may be lower if supercooling occurs or if there are impurities present in the water which could cause freezing point depression to occur. Under certain conditions, water may remain a liquid as cold as -40 to -42°
Explanation:
H3O+(aq) + OH-(aq) --> 2H2O (l)
NaHCO3(s) --> NaH 2+ (aq) + CO3 2- (aq)
NaH 2+ (aq) + H2O (l) --> Na+ (aq) + H3O+ (aq)
H2O (l) + CO3 2- (aq) --> OH- (aq) + HCO3- (aq)
(I'm not completely sure if I did the third question right) I'm sorry if I got it wrong