The oxidation state of Cr in K\(_2\)Cr\(_2\)O\(_7\) is?
+7
+6
+5
4
Correct answer is B
Potassium dichromate, K\(_2\)Cr\(_2\)O\(_7\)
→ [1 * 2] + [Cr * 2] + [-2 * 7] = 0
→ 2 + 2Cr - 14 = 0
→ 2Cr = 12
→Cr = \(\frac{12}{2}\) → 6
yellow to purple
orange to green
green to orange
purple to yellow
Correct answer is B
Reducing agent like SO\(_2\).
Sulphur dioxide gas (SO\(_2\)) is bubbled through acidified potassium dichromate. The orange solution turns green.
The salt formed from a reaction between citric acid and sodium hydroxide in solution will be?
acidic
basic
complex
neutral
Correct answer is B
Citric acid has 3 carboxyl groups, therefore, when reacts with NaOH, there is a simple salification reaction that will produce the trisodium citrate / sodium citrate. Trisodium citrate is a tribasic salt of citric acid. It is produced by complete neutralization of citric acid with high purity sodium hydroxide or carbonate and subsequent crystallization and dehydration.
What volume of 1.5M solution of KOH would contain 0.045 moles
67.50 cm3
30.00 cm3
6.75 cm3
3.00 cm3
Correct answer is B
No explanation has been provided for this answer.
The acid used in electrolysis of water is dilute?
HNO3
CH3COOH
H2SO4
HCl
Correct answer is C
The electrolyte is dilute sulfuric acid (= acidified water) which, during electrolysis is split into hydrogen and oxygen gases.