Single replacement means only 1 will bond. Ag + KNO3 --> AgNO3 + K
Just a rough sketch
Calculate the pOH first :
pOH =14-8.57=5.43
(OH)=10^-5.47
(OH)=3.72 x 10^-6 mol/L
0.115 M means that 0.115 moles of KBr are contained in a volume of 1000 ml, therefore a volume of 350 ml will have (0.115 × 0.35) = 04025 moles
From the formula of molarity moles = molarity × volume in liters
1 mole of KBr is equivalent to 119 g
Therefore, the mass = 0.04025 × 119 g = 4.79 g
The correct answer would be 0.1505 M/s. Given the rate of disapperance of HBr, we can easily calculate the rate of apearance of the products by looking at the coefficients of the substances in the reaction. In this case, for every two moles of HBr, 1 mole of Br2 is being produced so the reaction rate would be:
- 1/2 (r(HBr)) = rBr2
- 1/2 (-0.301) = rBr2
Rate of appearance of Br2 = 0.1505 M/s