Saliva's buffering capacity and flow of secretion are directly related to the rate and extent of demineralization. ... Saliva can act as a replenishing source and inhibit tooth demineralization during periods of low pH, while promoting tooth remineralization when the pH returns to a neutral state.
This problem could be solved through the Graham’s law of
effusion (also known as law of diffusion). This law states that the ratio of
the effusion rate of the first gas and effusion rate of the second gas is
equivalent to the square root of the ratio of its molar mass. Thus the answer
would be 0.1098.
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
26g --- 1 mol
56g --- X
X= 56/26 = 2,154 mol
959 ml = 959cm³ = 0,959dm³
C = n/V
C = 2,154/0,959
C = 2,246 mol/dm³