The number of moles that are 1.50 x10^23 molecules of NH3 are
=0.249 moles
<u><em> calculation</em></u>
The number of moles is calculated using Avogadro's law constant
that is According to Avogadro's law
1 moles of a substance = 6.02 x10^23 molecules
? moles = 1.50 x10^23 molecules
by cross multiplication
= [( 1.50 x 10^23 molecules x 1 moles) / (6.02 x10^23)] = 0.249 moles
Carbon tetrachloride looks like this
Cl
Cl-C-Cl
Cl
Whereas methane looks as so,
H
H-C-H
H
——————————————————————
In structure/geometry, they’re the exact same. They have the same surface area, and neither one is polar.
The only attribute to the difference in boiling points is the total molecular weights of the atoms
CH4 is MUCH lighter than CCl4, making the molecules easier to float around.
The solute is sodium chloride seeing as it is being dissolved. The solvent would be water.
Answer:
There are 198 grams of iron in a 450-gram sample of the ore.
Explanation:
From the given information:
Given that:
100-gram sample of iron ore is found in 44g of iron.
Thus. the grams of iron that can be found in a 450-gram sample of the iron ore can be computed as follows:
100g of iron ore = 44g of iron
450 gram of iron ore = x g of iron
x(g) of iron = ( 44g of iron × 450 gram of iron ore) / 100g of iron ore
x(g) of iron = 198 grams of iron
Thus, there are 198 grams of iron in a 450-gram sample of the ore.
7.5 ppm
<h3>Further explanation</h3>
Given
1000 g of water
0.0075g of Ca²⁺ ion
Required
the concentration in ppm by mass of Ca²⁺
Solution
ppm = part per million
solvent = water ⇒ ppm = 1 mg/L(water density is 1 kg / L) or mg/kg
Convert g to mg of Ca²⁺ ion :
0.0075 g = 7.5 x 10⁻³ g = 7.5 mg
Convert g to kg of water :
1000 g = 1 kg water
So the concentration of Ca²⁺ ion :
= 7.5 mg / 1 kg
= 7.5 ppm
