The activation energy Ea can be related to rate constant (k) at temperature (T) through the equation:
ln(k2/k1) = Ea/R[1/T1 - 1/T2]
where :
k1 is the rate constant at temperature T1
k2 is the rate constant at temperature T2
R = gas constant = 8.314 J/K-mol
Given data:
k1 = 0.543 s-1; T1 = 25 C = 25+273 = 298 K
k2 = 6.47 s-1; T = 47 C = 47+273 = 320 K
ln(6.47/0.543) = Ea/8.314 [1/298 - 1/320]
2.478 = 2.774 *10^-5 Ea
Ea = 0.8934*10^5 J = 89.3 kJ
This is an application of Boyle's law:
P₁V₁ = P₂V₂. we don't have to convert volume and pressure to standard forms. we can even use the pressure with mmHg
1 atm = 760 mmHg
V₂ = P₁V₁ / P₂ = 745 x 500 / 760 = 490 ml
Note that here we assume constant temperature
Answer:

Explanation:
We are given the formula:

This is a molecular formula, because it contains nonmetals.
1. Name the first element
The first element is phosphorous (P). Since this is the first element and there is only one, we don't need a prefix.
2. Second element
The second element is chlorine (Cl). It has a subscript of 5, so we must add the prefix of <u>hepta</u>-.
- Phosphorous heptachlorine
Add the ending of -ide.
- Phosphorous heptachloride
The prefix used for the second element is hepta. The compound name is phosphorous heptachloride.