Answer:
1 g
Explanation:
The half-life of Am-242 (16 h) is the time it takes for half of it to disappear.
We can make a table of the mass left after each half-life.
The mass remaining after 48 h is 1 g.
Answer:
The empirical formula = molecular formula = C13H18O2
Explanation:
in 100% compound we have 75.6 % Carbon ( Molar mass = 12g/mole), 8.80% hydrogen ( Molar mass = 1.01 g/mole) and 15.5% Oxygen (Molar mass = 16.01 g/mole).
Carbon: 75.6g / 12 = 6.29
Hydrogen: 8.80/ 1 = 8.80
Oxygen: 15.5/ 16 = 0.97
⇒0.97 is the smallest so we divide everything through by 0.97
C: 6.29 / 0.97 = 6.48 ≈ 6.5
H: 8.80 /0.97 = 9
O: 0.97 / 0.97 = 1
To get rid of decimals, we multiply by 2
C: 6.5 x 2 = 13
H: 9 x 2 = 18
O: 1 x 2 = 2
The empirical formula = C13H18O2
13x 12g/mol + 18x1g/mol + 2x 16g/mol = 156 + 18 + 32 = 206g/mol which is the molar mass of ibuprofen
The empirical formula = molecular formula = C13H18O2
Answer:
4.67M
Explanation:
The concentration of methanol (CH3OH) can be calculated using the following:
Molarity (M) = number of moles(n)/volume(v)
However, mole is not given. It can be obtained by using:
Mole = mass / molar mass
Where; mass = 34.4g
Molar mass (MM) of CH3OH is:
= 12 + 1(3) + 16 + 1
= 12 + 3 + 17
= 32g/mol
mole = 34.4/32
mole = 1.075mol
The volume needs to be converted to L by dividing by 1000
230mL = 230/1000
= 0.230L
Molarity = mol/volume
Molarity = 1.075/0.230
Molarity = 4.6739
Molarity = 4.67M
The concentration of CH3OH in solution is 4.67M
The Octet rule is a general rule of thumb that applies to most atoms. Basically, it states that every atom wants to have eight valence electrons in its outermost electron shell.
Answer: 123 g
Explanation: Q =It = nzF. For Ca^2+ z= 2, t = 5.5 x 3600 s and I = 30.0
And F= 96485 As/mol
Amount of moles is n = It /zF = 3.078 mol , multiply with atomic mass 40.08 g/mol
