Answer:
(a) weight percent of Cu = 44.59%
(b) weight percent of Zn = 53.49%
(c) weight percent of Pb = 1.91%
Explanation:
Given: Alloy contains- Cu=93.1 g, Zn=111.7 g, Pb=4.0 g
Therefore, the total mass of the alloy (m) = mass of Cu (m₁) + mass of Zn (m₂)+ mass of Pb (m₃)
m= 93.1 g + 111.7 g + 4.0 g = 208.8 g
(a) weight percent of Cu = (m₁ ÷ m)× 100% = (93.1 g ÷ 208.8 g)× 100% =44.59%
(b) weight percent of Zn = (m₂ ÷ m)× 100% = (111.7 g ÷ 208.8 g)× 100% =53.49%
(c) weight percent of Pb = (m₃ ÷ m)× 100% = (4.0 g ÷ 208.8 g)× 100% =1.91%
Answer:
paper chromatography is an analytical method used to separate colored chemicals or substances.It is primarily used as a teaching tool,having been replaced by other Chromatography methods ,such as thin layer chromatography.
Answer:
Explanation:
All buffer solutions have an effective range in which the buffer has a good regulation of pH.
This range is calculated by: pKa-1 < pH < pKa+1
The pH we need to control should be in that range. So for the phosphoric acid:
1) 
=> 2.2-1< pH < 2.2+1 => 1.2<pH<3.2
2) => 7.2-1< pH < 7.2+1 => 6.2<pH<8.2
3) 
=> 12.7-1< pH < 12.7+1 => 11.7<pH<13.7
For a pH=7.4 using a phosphate buffer we need to use diacid phosphate ()
