MCQ
The percentage of $Se$ in peroxidase anhydrous enzyme is $0.5\%$ by weight (atomic weight $=78.4$). Then minimum molecular weight of peroxidase anhydrous enzyme is
- ✓$1.568 \times {10^4}$
- B$1.568 \times {10^3}$
- C$15.68$
- D$3.136 \times {10^4}$
Minimum m.w. $ \to $molecule at least contain one selenium.
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The number of following statements which is/are correct about phenolphthalein is $.....$.
$A$. It can be used as an indicator for the titration of weak acid with weak base.
$B$. It begins to change colour at $pH =8.4$
$C$. It is a weak organic base
$D$. It is colourless in acidic medium
(Given that : $SrCO_{3(s)} \rightleftharpoons SrO_{(s)}+ CO_{2(g)} \,, K_p=1.6\,atm$)