A substance either an ion or a molecule that can act either an acid or a base depending on a medium is called Amphoteric. Some metals like zinc, tin, copper and aluminium which produce either metal oxides or hydroxides are examples of amphoteric. During the Amphoterism, the metal compound acts either an acid or a base depending on their oxidation state.
C. Answer correct I think…
Answer & Explanation: Acid rain occurs when sulfur dioxide and nitrogen oxide are released into the air to create a chemical reaction. When the two mix in the air (oxygen), they will get into the water and mix with other pollutants in the air, making acid rain.
The pressure of diver = atmospheric pressure + water pressure
atmospheric pressure = 750 mmHg (as given) = 750 / 760 atm = 0.987 atm
Water pressure is
P = hρg
where
h = height of water = 38 ft
1 ft = 0.3048
38 ft = 11.58 m
ρ = density = 1000 Kg / m³
g = gravitational constant = 9.81 m/s2
P = 11.58 X 1000 X 9.81 = 113599.8 Kg / m s^2 Or N /m^2
1 N / m^2 = 1 pa = 9.869 X 10^-6 atm
P = 113599.8 Pa = 1.12 atm
Total pressure = 1.12 + 0.987 atm = 2.107 atm = 2.1 atm (two significant figures)
It is false because an endothermic reaction will also start when energy is received from the environment when there is no solution involved