Answer: 0.5 moles
Explanation:
Cr2(SO3)2 is the chemical formula for chromium sulphate.
Given that,
Amount of moles of Cr2(SO3)2 (n) = ?
Mass of Cr2(SO3)2 in grams = 128.9g
For molar mass of Cr2(SO3)2, use the atomic masses:
Chromium, Cr = 52g;
Sulphur, S = 32g;
Oxygen, O = 16g
Cr2(SO3)2 =
(52g x 2) + [(32g + 16g x 3) x 2]
= 104g + [(32g + 48g) x 2]
= 104g + [80g x 2]
= 104g + 160g
= 264g/mol
Since, n = mass in grams / molar mass
n = 128.9g / 264g/mol
n = 0.488 mole [Round the value of n to the nearest tenth which is 0.5
Thus, there are 0.5 moles in 128.9 grams of Cr2(SO3)2
Answer:
Saturated solution
Explanation:
Saturated solution is the solution in which no more solute can be dissolved at a particular temperature.
A amount of the solute, potassium nitrate is dissolved at elevated temperature and on cooling, it precipitates. It means that the solution is saturated at that temperature. <u>Precipitation of the solute at lower temperature indicates that the solution is saturated solution.</u>
Answer:
3.65 g / ml correct to 3 sig. fig.
Explanation:
The computation of the concentration required is shown below:
As we know that
[A] = mass of solute ÷ volume of solution
Before that first find the mass of solute
Given that
Initial weight = 5.55g
And,
Final weight = 92.7 g
So,
Mass of KCl is
= 92.7 - 5.55
= 87.15 g ~ 87.2 g
Now the KCi is fully dissolved, so the volume is 23.9 ml
So, concentration is
= 87.2 g ÷ 23.9 ml
= 3.65 g / ml correct to 3 sig. fig.
Answer:
There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids)
Explanation:
There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions. ... Biological macromolecules are organic, meaning that they contain carbon.
