Answer
1. 1cm=10mm, 1kg=1000g and 12in=1 ft
2. 50mm=5cm
48 in =4ft
36ft=12 yd
2.5m=250cm
1000mL= 1 L
Explanation
if 1cm=10mm then 5cm=?
5×10=50mm
if 12 in =1ft then 48in=?
48/12 =4 ft
if 1m=100cm, then 2.5m=?
2.5×100= 250cm
and when know from capacity that 1000mL is equivalent to 1 liter.
The reaction of Mg Cl2 and KOH can be described as a double substitution type of reaction. This means the cations of the reactants are exchanged in places when the products are formed. In this case, the balanced reaction is expressed
MgCl2 (s) + 2KOH (aq) = Mhg (OH)2 (aq) + 2KCl (s)
Answer : The pH of the solution is, 9.63
Explanation : Given,
The dissociation constant for HCN = 
First we have to calculate the moles of HCN and NaCN.
and,
The balanced chemical reaction is:
Initial moles 0.1116 0.0461 0.08978
At eqm. (0.1116-0.0461) 0 (0.08978+0.0461)
0.0655 0.1359
Now we have to calculate the pH of the solution.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
Now put all the given values in this expression, we get:
Therefore, the pH of the solution is, 9.63
In a combustion of a hydrocarbon compound, 2 reactions are happening per element:
C + O₂ → CO₂
2 H + 1/2 O₂ → H₂O
Thus, we can determine the amount of C and H from the masses of CO₂ and H₂O produced, respectively.
1.) Compute for the amount of C in the compound. The data you need to know are the following:
Molar mass of C = 12 g/mol
Molar mass of CO₂ = 44 g/mol
Solution:
0.5008 g CO₂*(1 mol CO₂/ 44 g)*(1 mol C/1 mol CO₂) = 0.01138 mol C
0.01138 mol C*(12 g/mol) = 0.13658 g C
Compute for the amount of H in the compound. The data you need to know are the following:
Molar mass of H = 1 g/mol
Molar mass of H₂O = 18 g/mol
Solution:
0.1282 g H₂O*(1 mol H₂O/ 18 g)*(2 mol H/1 mol H₂O) = 0.014244 mol H
0.014244 mol H*(1 g/mol) = 0.014244 g H
The percent composition of pure hydrocarbon would be:
Percent composition = (Mass of C + Mass of H)/(Mass of sample) * 100
Percent composition = (0.13658 g + 0.014244 g)/(<span>0.1510 g) * 100
</span>Percent composition = 99.88%
2. The empirical formula is determined by finding the ratio of the elements. From #1, the amounts of moles is:
Amount of C = 0.01138 mol
Amount of H = 0.014244 mol
Divide the least number between the two to each of their individual amounts:
C = 0.01138/0.01138 = 1
H = 0.014244/0.01138 = 1.25
The ratio should be a whole number. So, you multiple 4 to each of the ratios:
C = 1*4 = 4
H = 1.25*4 = 5
Thus, the empirical formula of the hydrocarbon is C₄H₅.
3. The molar mass of the empirical formula is
Molar mass = 4(12 g/mol) + 5(1 g/mol) = 53 g/mol
Divide this from the given molecular weight of 106 g/mol
106 g/mol / 53 g/mol = 2
Thus, you need to multiply 2 to the subscripts of the empirical formula.
Molecular Formula = C₈H₁₀
Sorry If This Is Late***
<u>Elements can't be broken down</u>, into a simplre set of properties. They are one strict unit & cannot be broken down, however they can be added together to make a compound.
HOPE THIS HELPS & good luck <3 !!!!!
