Americium at standard temperature and pressure is solid. This element is a radioactive one and is a member of the actinide group. It was first produced by the group of Glenn T. Seaborg. It common application is in household smoke detectors.
Answer:
17.09g/L
Explanation:
Density = total mass of elements/ volume
We need to find the mass of each mixture constituents using their molar mass:
mole = mass/molar mass
For Neon (Ne) which contains 0.650mol;
0.650 = mass/20.18
mass = 0.650 × 20.18
mass = 13.12g
For Krypton (Kr) which contains 0.321mol;
0.321 = mass/83.79
mass = 0.321 × 83.79
mass = 26.89g
For Xenon (Xe) which contains 0.190mol;
0.190 = mass/131.3
mass = 0.190 × 131.3
mass = 24.95g
Total mass = 13.12g + 26.89g + 24.95g = 64.96g
Density = total mass / volume
Density = 64.96g / 3.80L
Density of the mixture = 17.09g/L
Answer:
1.40 M [OH⁻]
Explanation:
This compound dissociates into 3 ions, but since we are asked about [OH⁻], it's only 2. Therefore, multiply the molarity of the solution by the number of ions that [OH⁻] dissociates into:
2 × 0.70 M = 1.40 M
Hope this helps! Sorry that you got a link. Those are getting really annoying
Hi there!
We can use the following conversions to solve:
Total mass --> amount of mols --> amount of atoms (Avogadro's number)
Begin by calculating the amount of boron trifluoride in 3.61 grams:
3.61 g * (1 mol BF₃ / 67.8 g) ≈ 0.0532 mol BF₃
Use avogadro's number to convert:
0.0532 mol * 6.02× 10²³atoms / 1 mol = 3.203 × 10²² atoms
