Answer:
First step would be convert to moles
Final Answer: 37.8 g of NaCl
Explanation:
The reaction is:
2Na + Cl₂ → 2NaCI
We convert the mass of each reactant to moles:
18 g . 1mol /23g = 0.783 moles of Na
23g . 1mol / 70.9g = 0.324 moles of chlorine
We use the mole ratio to determine the limiting reactant:
Ratio is 2:1. 2 moles of Na react to 1 mol of chlorine
Then, 0.783 moles of Na, may react to (0.783 . 1)/2 = 0.391 moles.
Excellent!. We need 0.391 moles of Cl₂ and we only have 0.324 moles available. That's why the Cl₂ is our limiting reactant.
We use the mole ratio again, with the product side. (1:2)
1 mol of Cl₂ can produce 2 moles of NaCl
Then, our 0.324 moles of gas, may produce (0.324 . 2)/1 = 0.648 moles
Finally, we convert the moles to grams:
0.648 mol . 58.45g/mol =
Heat_1: Get the ice to 0 degrees
Convert 7 kg to grams
7 kg [1000 grams / 1 kg] = 7000 grams
Heat needed to get the the ice from - 9 to 0
deltat = 0 - -9 = 9 degrees
m = 7000 grams
c = 2.1 joules/gram
Heat_1 = m*c*deltat
Heat_1 = 7000 * 2.1 * 9
Heat_1 = 132,300 joules
Heat_2: Melt the ice.
There is no temperature change. The formula is 333 j/gram
Formula: H = mass * constant
H = 7000 g * 333 J / gram
H = 2331000 joules
Heat_3: Total amount of Joules needed.
2331000 + 132300 = 2 463 300 joules
Convert to Megajoules
2 463 300 joules * 1 megajoule / 1000000 = 2.63 megajoules.
It would be the same amount. So, 45 ml of NaOH is required to be added to the 45 ml of HCI to neutralize the acid fully. Here is a brief calculation:
Firstly, here is your formula: M(HCI) x V(HCI) = M(NaOh) x V(NaOH)
With the values put in: 0.35 x 45 = 0.35 x V(NaOH)
= 45 ml.
There is 45 ml of V(NaOH)
Let me know if you need anything else. :)
- Dotz
Answer:
Approximately 
(note that 
.)
Explanation:
The molarity of a solution gives the number of moles of solute in each unit volume of the solution. In this 
solution in water,
Let 
be the number of moles of the solute in the whole solution. Let 
represent the volume of that solution. The formula for the molarity 
of that solution is:
.
In this question, the volume of the solution is known to be 
. That's 
in standard units. What needs to be found is , the number of moles of in that solution.
The molar mass (formula mass) of a compound gives the mass of each mole of units of this compound. For example, the molar mass of is 
means that the mass of one mole of
.
For this question,
.
Calculate the molarity of this solution:
.
Note that 
(one mole per liter solution) is the same as 
.
