Answer:
D. For the atoms lower in the periodic table, the valence electrons are in higher energy levels and farther from the nucleus.
Explanation:
Atomic radius increases down the group because down the group, there an increase in the number of principle energy levels occupied. Now, these higher principal energy levels are made up of orbitals that are larger than the orbitals from the lower energy levels in size.
Therefore, the effect of this is that the greater number of principal energy levels will outweigh the increase in nuclear charge since nuclear charge also increases down the group and this in turn makes the atomic radius to increase as we go down the group.
Answer: 1.09 g
Explanation:
If we use the approximation that 1 mole is 22.4 L, then setting up a proportion,
- 1/22.4 = x/0.345 (x is the number of moles in the sample)
- x = 0.0154 mol
Since the mass of a mole of chlroine is about 70.9 g/mol, (0.0154)(70.9) = 1.09 g (to 3 s.f.)
Answer:
Molarity = 0.24 mol/L
Explanation:
Given data:
Mass of NaNO3 = 25.4 g
Volume of solution = 1250 mL
Molarity = ?
Solution:
Molarity of solution is equal to the number of moles of solute divided by volume of solution in litter.
Formula:
Molarity = number of moles / volume in L
First of all we will convert the volume in litter.
1 L = 1000 mL
1250 / 1000 = 1.25 L
Now we calculate the moles of NaNO3 in present in 25.4 g.
Number of moles = mass / molar mass
Molar mass of NaNO3 = (23 + 14+ 16×3) = 85 g/mol
Number of moles = 25.4 g / 85 g/mol
Number of moles = 0.299 mol
Now we will calculate the molarity of solution
Molarity = number of moles / volume in L
Molarity = 0.299 mol / 1.25 L
Molarity = 0.24 mol/L
The chemical reaction is
<span> M2+(aq) + 2L(aq) <==> ML22+(aq)
</span>Intial concentration 0.10 0.10
Change -x -2x +x
Equilibrium 0.10 - x 0.01 = 0.10 - 2x x
Solving for x
0.01 = 0.10 - 2x
x = 0.045
The equilibrium concentration of ML22+ is 0.045 mol L-1
Answer:
18.2784 g
Explanation:
First we <u>convert 180 lb to kg</u>:
- 180 lb * 0.453 kg / lb = 81.6 kg
Now we <u>calculate the mass of antibiotic taken in one day</u>:
- 8.0 mg/kg * 81.6 kg = 652.8 mg
Given that it is taken twice daily, <em>in one day the person would take (652.8 * 2) 1305.6 mg</em>. In grams that mass would be:
- 1305.6 mg / 1000 = 1.3056 g
Finally we multiply those 1.3056 daily grams by the 14 days in two weeks:
- (1.3056 g) * 14 = 18.2784 g