Answer: Option A) 83.9g
Explanation:
KCl is the chemical formula of potassium chloride.
Given that,
Amount of moles of KCl (n) = ?
Volume of KCl solution (v) = 0.75L
Concentration of KCl solution (c) = 1.5M
Since concentration (c) is obtained by dividing the amount of solute dissolved by the volume of solvent, hence
c = n / v
make n the subject formula
n = c x v
n = 1.5M x 0.75L
n = 1.125 mole
Now given that,
Amount of moles of KCl (n) = 1.125
Mass of KCl in grams = ?
For molar mass of KCl, use the molar masses of:
Potassium, K = 39g;
Chlorine,Cl = 35.5g
KCl = (39g + 35.5g)
= 74.5g/mol
Since, amount of moles = mass in grams / molar mass
1.125 mole = m / 74.5g/mol
m = 1.125 mole x 74.5g/mol
m = 83.81g
Thus, 83.9 grams of KCl are needed to prepare 0.750 L of a 1.50 M solution in water
Answer:
3.2043 x 10²³
Explanation:
No. of Mole of lead (Pb) = 0.532 mol
No. of atoms of lead = ?
Solution:
Formula Used to calculate
no. of moles = numbers of particles (ions, molecules, atoms) /Avogadro's number
Avogadro's no. = 6.023 x10²³
So,
The formula could be written as
no. of atoms of lead Pb = no. of moles x 6.023 x10²³
Put the values in above formula
no. of atoms of lead Pb = 0.532 mol x 6.023 x10²³
no. of atoms of lead Pb = 3.2043 x 10²³
so 3.2043 x 10²³ atoms of lead are contained in 0.532 mole.
Answer:
The solid particles will be trapped behind on the strainer while the liquid molecules will pass or filter through.
Explanation:
Filtration is a process of separation of mixtures involving an insoluble solid and a fluid such as liquids or gases using a filtering medium such as paper or cloth or any other material. During the process, the liquid molecules pass through the filtering medium whereas the solid particles are not allowed to pass through but are retained by the medium. The reason is that the pores on the filtering medium are only small enough for the liquid molecules to pass through but not the solid particles.
An example of a mixture that can be separated through filtration is a suspension of chalk and water. Also, a mixture of water and solid particles such as water and tea leaves can also be separated using a strainer with cloth.
In the question, if a mixture of insoluble solids in a liquid is passed through a strainer with cloth, the solid particles will be trapped behind on the strainer while the liquid molecules will pass through.
Answer: An atom can be considered unstable in one of two ways. If it picks up or loses an electron, it becomes electrically charged and highly reactive. Such electrically charged atoms are known as ions. Instability can also occur in the nucleus when the number of protons and neutrons is unbalanced.
Explanation:
Without plastic, we wouldn't have as much of an environmental problem as we have now. Even though plastic has a lot of negatives, it's also made our lives a lot easier over past years. ... Our cars would have been different since a lot of the materials used inside are made out of plastic.
