Ice floats because it is less dense than water. When water freezes, it creates a crystal lattice that occupies more volume than the water did. Because it is less dense, ice is displaced by water (and floats on top).
:)
Given reactions:
(A) 6CO2(g) + 6H2O(l) + sunlight → C6H12O6(aq) + 6O2(g)
(B) 2H2(g) + O2(g) → 2H2O(g) + energy
Exothermic reactions are those which proceed with the release of heat/energy. In contrast, endothermic reactions proceed with the absorption of energy in the form of heat or light.
Since reaction A required sunlight, it is endothermic. Reaction B releases energy, hence exothermic
Ans: (B)
A is endothermic
B is exothermic
Answer:
5.85 grams of NaCl should be added to 250 grams of water to make a 0.40 m solution.
Explanation:

Mass of NaCl =x
Molar mass of NaCl = 58.5 g/mol
Molality of the solution = 0.40 m
Mass of the solvent = 250 g = 0.250 kg (1g = 0.001 kg)


5.85 grams of NaCl should be added to 250 grams of water to make a 0.40 m solution.
A. It is not a solid and not a linguist
Answer:
By decreasing the volume, the equilibrium will shift to the side with the smallest amount of particles
Explanation:
Step 1: Data given
The principle of Le Chatelier says:
When the volume is decreased, the equilibrium will shift to the side of the smallest number of particles.
2NOBr(g) ⇌ 2NO(g)+Br2(g)
In the following example, we have 2 moles of NOBr (on the left side) and 3 moles of gas on the right side. This means the left side, the reactant side, has the smallest number of particles.
The equilibrium will here shift to the left side, the side of NOBr.
In the following example
2NO2(g) ⇌ N2O4(g)
We have 2moles of NO2 on the left side and 1 mol of N2O4 on the right side.
By decreasing the volume, the equilibrium will shift to the side of the smallest number of moles. Here this is the right side, the side of N2O4.