is a type of energy wich start off any reaction
Answer:
15912 × 10∧-19 KJ
Explanation:
Given data;
frequency of photon = 2.4 × 10^18 1/s.
Planck's constant = 6.63 × 10∧-34 j.s
Energy = ?
Formula:
E = h × ν
E = 6.63 × 10∧-34 j.s × 2.4 × 10^18 1/s
E= 15.912 × 10∧-16 j
now we will convert the joule into kilo joule,
E = 15.912 × 10∧-16 j /1000 = 15.912 × 10∧-19 KJ
Answer:
Option a.
0.01 mol of CaCl₂ will have the greatest effect on the colligative properties, because it has the biggest i
Explanation:
To determine which of the solute is going to have a greatest effect on colligative properties we have to consider the Van't Hoff factor (i)
These are the colligative properties:
ΔP = P° . Xm . i → Lowering vapor pressure
ΔT = Kb . m . i → Boiling point elevation
ΔT = Kf . m . i → Freezing point depression
π = M . R . T → Osmotic pressure
Van't Hoff factor are the numbers of ions dissolved in the solution. For nonelectrolytes, the i values 1.
CaCl₂ and KNO₃ are two ionic solutes. They dissociate as this:
CaCl₂ → Ca²⁺ + 2Cl⁻
We have 1 mol of Ca²⁺ and 2 chlorides, so 3 moles of ions → i = 3
KNO₃ → K⁺ + NO₃⁻
We have 1 mol of K⁺ and 1 mol of nitrate, so 2 moles of ions → i = 2
Option a, is the best.
"The reaction is exothermic and ΔH is negative" can be understood about the reaction and the enthalpy change (ΔH) during the reaction.
<u>Option: D</u>
<u>Explanation:</u>
When the reaction is positive, the process becomes endothermic, i.e. heat appears to be consumed by the system because the reaction products are more enthalpic than the reactants. When the reaction is negative, on the other hand, the process is exothermic, which is the total decrease in enthalpy is caused by heat production. Here the initial temperature is 21.0 C but increase in final temperature to 38.8 C, because if some processes require heat, others must give off heat when they take place.
Answer:
hydrate
Explanation:
when a hydrate is heated,it changes color due to the exothermic reaction taking place.the structure of the complex changes but not entirely.this result in the sample to to not dissolve completely and we can observe the small traces of the sample.
