<span>Calculating average atomic mass is exactly like calculating a weighted average. Perform the following calculation:
(mass1)(percentage1) + (mass2)(percentage2) = average atomic mass
(35.0)(0.75) + (37.0)(0.25) = average atomic mass
Make sure your percentages are in decimal form for this calculation.
One of the other answers given is correct, though the explanation is lacking a bit. Two of the answers can be eliminated immediately: 35.0 amu and 37.0 amu cannot be the average. If the mixture of isotopes was 50% and 50%, then 36.0 amu would be correct; however, the mixture is 75/25. This leaves only one possible answer choice.</span>
[H+] in first brand:
4.5 = -log([H+])
[H+] = 10^(-4.5)
[H+] in second brand:
5 = -log[H+]
[H+] = 10^(-5)
Difference = 10^(-4.5) - 10^(-5)
= 2.2 x 10⁻⁵
The answer is A.
The reaction that is a double displacement reaction is the final one. Between Pb(NO3)2 and HCl.
Number of moles = 5 x 10^24 / 6.02 x 10^23 = 8.305 moles. Volume= moles x 22.4 = 186.032 liters. Hope this helps!
Answer:
C₄F₈
Explanation:
Using their mole ratio to compute their mass
molar mass of carbon = 12.0107 g/mol
molar mass of fluorine gas = 37.99681
let x = mass of carbon
given mass of fluorine = 1.70 g
x / 12.01067 = 1.70 / 37.99687
cross multiply
x = ( 1.70 × 12) / 37.99687 = 20.4 / 37.99687 = 0.53688 g
mass of one mole of CF₂ = 0.53688 + 1.70 = 2.23688 g
number of mole of CF₂ = 8.93 g / 2.23688 = 3.992 approx 4
molecular formula of CF₂ = 4 (CF₂) = C₄F₈
