Answer:
.
Explanation:
Lithium is in the first column of the periodic table, so it will have 1 valence electron.
Bromine is in the seventh column of the periodic table, so it will have seven valence electrons.
They must combine in a way to reach 8.
When combining elements to form compounds, the "crisscross method" is used. Above Li would be a charge of +1, and above Br would be a charge of -1.
Cross the 1 from the top of Li to the bottom of Br, and so there is 1 Br.
Cross the 1 from the top of Br to the bottom of Li, and so there is 1 Li.
It is not written BrLi because chemists decided to order them the other way. Technically speaking, it isn't wrong, but the positive charge is normally put on the left and the negative charge is normally put on the right.
After 3 years, the substance will go through 4 half lives. You can do 230*(1/2)^4, which is 14.375.
1) Find the number of mols of HCl in 5.2 liters of 4.0M solution:
n = M*V(L) = 4.0 mol/L * 5.2 L = 20.8 mol
2) Find the number of mols of Mg that will react with 20.8 mol of HCl, using the coefficients of the balanced equation
[1mol Mg / 2 mol HCl] * 20.8 mol HCl = 10.4 mol Mg
3) Transform mol to mass using the atomic mass:
10.4 mol Mg * 24.3 g/mol = 252.7 g of Mg.
Answer:
150.1 mL
Explanation:
Step 1: Given data
- Density of benzene (ρ): 0.879 g/mL
- Mass of the sample of benzene (m): 131.9 g
- Volume of the sample of benzene (V): ?
Step 2: Calculate the volume of the sample of benzene
Density is an intrinsic property. It is equal to the quotient between the mass and the volume of the sample of benzene.
ρ = m/V
V = m/ρ
V = 131.9 g/(0.879 g/mL)
V = 150.1 mL
