<h3>
Answer:</h3>
0.699 mole CaCl₂
<h3>
Explanation:</h3>
To get the number of moles we use the Avogadro's number.
Avogadro's number is 6.022 x 10^23.
But, 1 mole of a compound contains 6.022 x 10^23 molecules
In this case;
we are given 4.21 × 10^23 molecules of CaCl₂
Therefore, to get the number of moles
Moles = Number of molecules ÷ Avogadro's constant
= 4.21 × 10^23 molecules ÷ 6.022 x 10^23 molecules/mole
= 0.699 mole CaCl₂
Hence, the number of moles is 0.699 mole of CaCl₂
The trick for this problem is to understand atomic mass: the fact that different atoms have different masses. What we need to do is add up all the atomic masses of the compound and work out the ratio of mass of water to the mass of sodium carbonate. Atomic masses are often given for each atom in the periodic table, but you can look them up on google too.
You can do this by adding up individual atoms for each molecule, or you can shortcut and lookup the molar mass of the compound (i.e.the task already done for you).
The molar mass of water is 18.01g/mole so for 10 moles of water we have a mass of 180.1g.
The molar mass of sodium carbonate is 106g/mole (google).
So the total mass of the sodium carbonate decahydrate compound is 180.1+106 = 286.1g, of which water would make up 180.1g, so the percentage of water is is 180.1/286.1 = 0.629, so we can round this to 63%
:)
So the put a lot of words to make this seem more complicated than it is. Your first equation involves the money. I’m going to use x to represent tacos and y to represent burritos.
3x+7.25y=595 would be your first equation because you know the price of each item already just not how many. The second would involve the twice as many burritos sold than tacos. So that would mean x+2 would equal y
Y=x+2
Hope this helps. If not I can explain it more in detail.
I’m writing this equation by memory, so I hope I’m correct. It’s been about four months since we used in in my chem class:
(P-(n^2•a)/V^2)(V-nb)=nRT
Plugging in values given:
(P-(1•1.35)/(1.42^2))(1.42-(1•0.0322))=(1)(0.0821)(300)
(P-(1.35/2.016))(1.42-0.0322)=24.63
(P-(1.35/2.016))=17.75
P=18.42 atm
The pressure exerted by the Argon would be 18.42 atmospheres.
