Answer:
O D. It has an -OH group attached to the end of the molecule.
Explanation:
Some alcohols have hydroxyl group (OH) attached to the end of a molecule and some have it attached as a branch on the molecule
- R is aryl or alkyl group
- OH is hydroxyl group
Molality is defined as the number of moles of solute in 1 kg of solvent.
molality of solution to be prepared is 0.50 molal
this means that in 1000 g of water there should be 0.50 mol of NaCl
if 1000 g of water should contain - 0.50 mol
then 750.0 g of water requires - 0.50 mol/kg x 0.750 kg = 0.375 mol
mass of NaCl in 0.375 mol - 58.5 g/mol x 0.375 mol = 21.9 g
therefore a mass of 21.9 g of NaCl is required
Answer:
Both are endothermic reactions.
Explanation:
Chemical equation:
1/2H₂(g) + 1/2I₂(g) → HI(g) + 6.2 kcal/mol
Chemical equation:
21.0 kcal/mol + C(s) + 2S(s) → CS₂
Both reaction are endothermic because heat is added in both of reactions.
Endothermic reactions:
The type of reactions in which energy is absorbed are called endothermic reactions.
In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.
For example:
C + H₂O → CO + H₂
ΔH = +131 kj/mol
it can be written as,
C + H₂O + 131 kj/mol → CO + H₂
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Answer:
See explanation
Explanation:
We know that photosynthesis involves the combination of carbon dioxide and water in the presence of sunlight to yield glucose.
If the atmosphere is rich in carbon dioxide such as in a green house where air is filled with carbon dioxide, the rate of photosynthesis is increased.
As the rate of photosynthesis is increased, the growth of plants is also increased.
Hence, in a greenhouse where the air contains more carbon dioxide, the rate of plant growth increases.
Balanced equation:
Pb(SO₄)₂ + 2 Zn → 2 ZnSO₄ + Pb
From the equation we found that 2 moles of Zn form 2 moles of ZnSO₄
so 0.582 mole of Zn will produce 0.582 ZnSO₄
Molar mass of ZnSO₄ = 161.47 g/mole
Mass of ZnSO₄ formed = 161.47 x 0.582 = 94.0 grams
