Activation energy is the energy required by reactants to undergo chemical reaction and given products
Every reactant has some internal energy (sum of all kind of energy like kinetic energy, potential energy, mechanical energy, chemical energy etc). It needs some extra energy to undergo chemical reaction which is activation energy
All kinds of reaction whether exothermic or endothermic needs activation energy
Threshold energy = internal energy + activation energy
The answer is B, you just check if it is the same on the left and right side
A:
Left side - Right side
2xH - 2xH
1xS - 3xS
4xO - 12xO
2xAl - 2xAl
Therefore A is not correct
B:
Left side - right side
2xK - 2xK
1xCl - 1xCl
1xPb - 1xPb
2xN - 2xN
6xO - 6xO
B is therefore correct as both sides add up
but heres a way to solve it
An athlete takes a deep breath, inhaling 1.85 L of air at 21°C and 754 mm Hg.
T
How many moles of air are in the breath? How many molecules?
Gas constant, R= 8.314 J mol ¹ K-1
PV = nRT
PV
RT
h=
=
P
= 0.08206 L atm mol-1 K-1
= 62.36 L Torr mol-1 K-1 -
1 atm = 760 mm Hg = 760 Torr
754 Forr 1.85€
6236 Jerr 294K
Answer:
It takes 5.83s to decrease the concentration of the reactant from 0.537M to 0.100M
Explanation:
A zero-order reaction follows the equation:
[A] = [A]₀ - kt
<em>Where [A] is actual reaction of the reactant = 0.100M</em>
<em>[A]₀ the initial concentration = 0.537M</em>
<em>k is rate constant = 0.075Ms⁻¹</em>
<em>And t is time it takes:</em>
<em />
0.100M = 0.537M -0.075Ms⁻¹t
-0.437M = -0.075Ms⁻¹t
5.83s = t
It takes 5.83s to decrease the concentration of the reactant from 0.537M to 0.100M
Silver chloride produced : = 46.149 g
Limiting reagent : CuCl2
Excess remains := 3.74 g
<h3>Further explanation</h3>
Reaction
silver nitrate + copper(II) chloride ⇒ silver chloride + copper(II) nitrate
Required
silver chloride produced
limiting reagent
excess remains
Solution
Balanced equation
2AgNO3 (aq) + CuCl2 (s) → 2AgCl(s) + Cu(NO3)2(aq)
mol AgNO3 :
= 58.5 : 169,87 g/mol
= 0.344
mol CuCl2 :
=21.7 : 134,45 g/mol
= 0.161
mol ratio : coefficient of AgNO3 : CuCl2 :
= 0.344/2 : 0.161/1
= 0.172 : 0.161
CuCl2 as a limiting reagent
mol AgCl :
= 2/1 x 0.161
= 0.322
Mass AgCl :
= 0.322 x 143,32 g/mol
= 46.149 g
mol remains(unreacted) for AgNO3 :
= 0.344-(2/1 x 0.161)
= 0.022
mass AgNO3 remains :
= 0.022 x 169,87 g/mol
= 3.74 g
