Answer : The balanced chemical equation is,

Explanation :
Rules for the balanced chemical equation in basic solution are :
- First we have to write into the two half-reactions.
- Now balance the main atoms in the reaction.
- Now balance the hydrogen and oxygen atoms on both the sides of the reaction.
- If the oxygen atoms are not balanced on both the sides then adding water molecules at that side where the more number of oxygen are present.
- If the hydrogen atoms are not balanced on both the sides then adding hydroxide ion
at that side where the less number of hydrogen are present. - Now balance the charge.
The half reactions in the basic solution are :
Reduction :
......(1)
Oxidation :
.......(2)
Now multiply the equation (1) by 2 and then added both equation, we get the balanced redox reaction.
The balanced chemical equation in a basic solution will be,

If I'm not mistaking the answer is C. Reactiviy with oxygen. Hopfully I'm correct and I hope it helps!
Answer:
1.368 grams of manganese dioxide must b added to HCl to obtain 385 mL of chlorine gas.
Explanation:
Using ideal gas equation:
PV = nRT
where,
P = Pressure of chlorine gas = 
1 atm = 760 Torr
V = Volume of chlorine gas = 385 mL = 0.385 L ( 1 mL - 0.001 L)
n = number of moles of chlorine gas = ?
R = Gas constant = 0.0821 L.atm/mol.K
T = Temperature of chlorine gas =25 °C= 25 + 273 K = 300 K
Putting values in above equation, we get:


According to reaction, 1 mole of chlorine gas is obtained from 1 mole of manganese dioxide ,then 0.01573 moles of chlorine gas will be obtained from :
of manganese dioxide
Mass of 0.01573 moles of manganese dioxide:
0.01573 mol × 86.94 g/mol = 1.368 g
1.368 grams of manganese dioxide must b added to HCl to obtain 385 mL of chlorine gas.
Answer:
a b c are correct and rest of other are incorrect
The answer is Boyle's law. Boyle's law states that the volume of a fixed mass of a gas is inversely proportional to its pressure at a constant absolute temperature.
That is; V α 1/P , at constant temperature and a fixed amount of the gas.
Such that V= k/P where k is a constant