Answer:
m
Explanation:
These abbreviations are used for both singular and plural units of measure, so “ft” is the abbreviation for foot and for feet and “m” is the abbreviation for meter and for meters.
Permeable materials for what
Group 1 and group 7 of element group consists of alkali metal, which are generally combined with other elements in nature, so they have properties of compound
Answer:
Eqv Pt pH = 8.73
Explanation:
HOAc + NaOH => NaOAc + H₂O
50ml(0.10M HOAc) + 50ml(0.10M NaOH) => 100ml(0.05M NaOAc) + H₂O
For neutralized system, 100ml of 0.05M NaOAc remains
NaOAc => Na⁺ + OAc⁻
Na⁺ + H₂O => No Rxn
OAc⁻ + H₂O => HOAc + OH⁻
C(i) 0.05M ----- 0M 0M
ΔC -x ----- +x +x
C(f) 0.05-x
≅ 0.05M ----- x x
Kb = Kw/Ka = [HOAc][OH⁻]/[OAc⁻] = 1 X 10⁻¹⁴/1.7 X 10⁻⁵ = (x)(x)/(0.05M)
=> x = [OH⁻] = SqrRt(0.05 x 10⁻¹⁴/1.7 x 10⁻⁵) = 5.42 x 10⁻⁶M
=> pOH = -log[OH⁻] = -log(5.42 x 10⁻⁶) = 5.27
pH + pOH = 14 => pH = 14 - pOH = 14 - 5.27 = 8.73 Eqv Pt pH
Answer:
a) 210 mL of 95% ethanol
b) 75 mL of water
Explanation:
a) We can use the dilution equation to solve this problem. C₁ and V₁ are the concentration and volume of the stock solution, respectively, while C₂ and V₂ are the concentration and volume of the diluted solution.
C₁V₁ = C₂V₂
We want to find V₁, the volume of ethanol stock we need to dilute to prepare the final solution:
V₁ = (C₂V₂) / C₁
The concentrations are represented in percentages. We substitute in the known values to calculate V₁. The units cancel to leave us with units of mL.
V₁ = (C₂V₂) / C₁ = (70%)(285mL) / (95%) = 210 mL
b) The final solution volume is 285 mL and we have added 210 mL of ethanol, so the remaining volume is from the water that we add:
(285 mL - 210 mL) = 75 mL