Answer:
k₂ = 4.06 x 10⁻² s⁻¹.
Explanation:
- From Arrhenius law: <em>K = Ae(-Ea/RT)</em>
where, K is the rate constant of the reaction.
A is the Arrhenius factor.
Ea is the activation energy.
R is the general gas constant.
T is the temperature.
- At different temperatures:
<em>ln(k₂/k₁) = Ea/R [(T₂-T₁)/(T₁T₂)]</em>
k₁ = 5.8 × 10⁻³ s⁻¹, k₂ = ??? , Ea = 33600 J/mol, R = 8.314 J/mol.K, T₁ = 298.0 K, T₂ = 348.0 K.
- ln(k₂/5.8 × 10⁻³ s⁻¹) = (33600 J/mol / 8.314 J/mol.K) [(348.0 K - 298.0 K) / (298.0 K x 348.0 K)] = (4041.37) (4.82 x 10⁻⁴) = 1.9479.
- Taking exponential of both sides:
(k₂/5.8 × 10⁻³ s⁻¹) = 7.014.
∴ k₂ = 4.06 x 10⁻² s⁻¹.
Answer:
Density
Explanation:
Density is defined as the mass per unit volume. It is the ratio between the mass and the volume of a substance. It does not matter how large or small a sample of matter is, the same substance will always have the same density, because of this. The ratio between the mass and volume remains the same.
<span>Fe(OH)3(S) +3HNO3(aq)----->Fe(NO3)3(aq) + 3H20(aq)
M(Fe(OH)3)=56+48+3=107; M(HNO3)= 48+14+1=63
n(Fe(OH)3)=5.4/107=0.05; n(HNO3)=2.6/63=0.04
n(Fe(OH)3):n(HNO3)=1:3, which means that the HNO3 should be three times (molar) than the Fe(OH)3, but you can see that it is, actually, even less than the Fe(OH)3, meaning that HNO3 is the limiting reagent and the amount of Fe(OH)3 which is going to react with HNO3 is 0.04/3=0.013 i.e. 0.05-0.013=0.037 mol Fe(OH)3 is left after the completion.
Just in case you can convert it into mass, but I suppose this is enough.</span>
Answer:
1/ Using the first letter of the name of the elements.
2/ If the name of two or more elements begins with the same letter,the second letter of their name is also taken with first letter.
3/ Symbols are made by using the letters of the name of elements in other languages also.
