Answer : The molecular weight of a substance is 157.3 g/mol
Explanation :
As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.
Mass of solute = 7 g
Mass of solution = 100 g
Mass of solvent = 100 - 7 = 93 g
Formula used :
where,
= change in freezing point
= temperature of pure water = 
= temperature of solution = 
= freezing point constant of water = 
m = molality
Now put all the given values in this formula, we get
Therefore, the molecular weight of a substance is 157.3 g/mol
A is the answer im pretty sure
There are 2 molecules of Carbon dioxide(CO2)
<h3>Further explanation</h3>
Given
Molecules of CO2
Required
The number of molecules
Solution
The coefficient of a molecule shows the number of that molecule, while the subscript after the name of the atom indicates the number of that atom in the molecule
Because there is a coefficient of 2 in front of the CO2 molecule, then the number of CO2 molecules is 2
Answer:
B. Na
Explanation:
To identify an atom, you simply need to look at the number of protons. This atom has 11 protons. On the periodic table, you can see that the element with 11 protons is sodium (Na).
It is a <u><em>chemical compound</em></u> formed with a metal (mainly positive cations) with oxygen.
It is formed through the air as they react in the air together.
They are also BASES - ALKALINE (so neutralise acids)
