Answer:
120g
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
Sn + 2HF —> SnF2 + H2
Next, we shall determine the number of mole of HF needed to react with 3 moles of Sn.
From the balanced equation above, 1 mole of Sn reacted with 2 moles of HF.
Therefore, 3 moles of Sn will react with = 3 x 2 = 6 moles of HF.
Finally, we shall convert 6moles of HF to grams
This is illustrated below:
Number of mole of HF = 6moles
Molar Mass of HF = 1 + 19 = 20g/mol
Mass of HF =..?
Mass = number of mole x molar Mass
Mass of HF = 6 x 20
Mass of HF = 120g
Therefore, 120g of HF is needed to react with 3 moles of Sn
Answer:
C. Double Replacement
Explanation:
A. Wrong because SR uses a compound and element. This equation is a compound and compound.
B. Wrong because it does not have O2 in the formula. All combustion reactions must have O2.
C. Correct because it is a compound reacting with a compound.
D. Wrong because the reactants did not form a single product. ex. (x + y > xy)
E. Wrong because the equation did not start with a single compound and break down. ex. (xy > x + y)
Energy is the ability to do work
The correct method would be multiplying the speed of light by the time it takes to travel from the moon to Earth. This is because:
S=So+V*t
In which:
S= space
So= space at the start (origin)
V=speed or velocity
t=time
By multiplying miles/second by seconds you get miles as a result.
By taring a balance the process of weighing by difference is done automatically. When a balance is tared with an object on the balance pan, the weight of the object will be automatically subtracted from every reading until the balance is re-tared or zeroed.
