A. More neutrons than protons
Answer:
12.6.
Explanation:
- We should calculate the no. of millimoles of KOH and HCl:
no. of millimoles of KOH = (MV)KOH = (0.183 M)(45.0 mL) = 8.235 mmol.
no. of millimoles of HCl = (MV)HCl = (0.145 M)(35.0 mL) = 5.075 mmol.
- It is clear that the no. of millimoles of KOH is higher than that of HCl:
So,
[OH⁻] = [(no. of millimoles of KOH) - (no. of millimoles of HCl)] / (V total) = (8.235 mmol - 5.075 mmol) / (80.0 mL) = 0.395 M.
∵ pOH = -log[OH⁻]
∴ pOH = -log(0.395 M) = 1.4.
∵ pH + pOH = 14.
∴ pH = 14 - pOH = 14 - 1.4 = 12.6.
Answer:
m = 575 g
Explanation:
Given data:
Volume of solution = 0.500 L (0.500×1000 = 500 mL)
Density of glucose solution = 1.15 g/mL
Mass of glucose solution = ?
Solution:
Formula:
d = m/v
d = density
m = mass
v = velocity
Now we will put the values in formula.
1.15 g/mL = m/500 mL
m = 1.15 g/mL × 500 mL
m = 575 g
Answer:
C.
Explanation:
They will need to know the influence of gravitational force on objects because gravity can affect an objects weight.
Let's break this down. We know from our balanced equation that (in theory) we'll get the same number of moles of copper out of the reaction that we put into it. So we need to find the number of moles of CuSO4 we have in 200.0 grams. Using the molar mass of CuSO4:
200.0 grams CuSO4 * (1 mole CuSO4)/(159.61 grams CuSO4) =
1.253 moles CuSO4
We know that the moles of CuSO4 and Cu are one-to-one, so we should yield the same number of moles of copper. If we multiply by copper's molar mass, we get:
1.253 moles Cu * (63.55 grams Cu)/(1 mole Cu) = 79.63 grams Cu