What types of atoms typically form covalent bonds?
The correct answer:
d) Nonmetals with nonmetals, because their difference in electronegativity is below 1.7.
En example to explain:
An example of a covalent bonding: HCl -> 2 nonmentals
-> a difference in electronegativity less than 1.7:
EN(Cl) = 3.0 and EN (H) = 2.1 (you can search these values in a periodic table)
/\EN = 3.0 - 2.1 = 0.9
0.9 < 1.7
I hope this helped you out!
To determine which order of the reaction it is, first we need to calculate the rate of change of moles.
the data is as follows
time 0 40 80 120 160
moles 0.100 0.067 0.045 0.030 0.020
Q1)
for the first 40 s change of moles ;
= -d[A] / t
= - (0.067-0.100)/40s
= 8.25 x 10⁻⁴ mol/s
for the next 40 s
= -(0.045-0.067)/40
= 5.5 x 10⁻⁴ mol/s
the 40 s after that
= -(0.030-0.045)/40 s
= 3.75 x 10⁻⁴ mol/s
k - rate constant
and A is the only reactant that affects the rate of the reaction
rate = k [A]ᵇ
8.25 × 10⁻⁴ mol/s = k [0.100 mol]ᵇ ----1
5.5 x 10⁻⁴ mol/s = k [0.067 mol]ᵇ -----2
divide the 2nd equation by the 1st equation
1.5 = [1.49]ᵇ
b is almost equal to 1
Therefore this is a first order reaction
Q2)
to find out the rate constant(k), we have to first state the equation for a first order reaction.
rate = k[A]ᵇ
As A is the only reactant thats considered for the rate equation.
Since this is a first order reaction,
b = 1
therefore the reaction is
rate = k[A]
substituting the values,
8.25 x 10⁻⁴ mol/s = k [0.100 mol]
k = 8.25 x 10⁻⁴ mol/s /0.100mol
= 8.25 x 10⁻³ s⁻¹
The weathering process caused by cycles of freezing and thawing of water in surface pores, cracks, and other openings
Find your answer in the explanation below.
Explanation:
PV = nRT is called the ideal gas equation and its a combination of 3 laws; Charles' law, Boyle's law and Avogadro's law.
According to Boyle's law, at constant temperature, the volume of a gas is inversely proportional to the pressure. i.e V = 1/P
From, Charles' law, we have that volume is directly proportional to the absolute temperature of the gas at constant pressure. i.e V = T
Avogadro's law finally states that equal volume of all gases at the same temperature and pressure contain the same number of molecules. i.e V = n
Combining the 3 Laws together i.e equating volume in all 3 laws, we have
V = nT/P,
V = constant nT/P
(constant = general gas constant = R)
V = RnT/P
by bringing P to the LHS, we have,
PV = nRT.
Q.E.D
The correct answer is 7 I just took the test :)
