Which of the following compounds on oxidation gives methyl ethyl ketone?

The pair of compounds,which cannot exist together in a solution is

The concentration of hydrogen ion in a sample of soft drink is $3.8 \times 10^{-3} \, M$. What is its $pH$ (in $.42$)?

In gene therapy of adenosine deaminase $\text{(ADA)}$ deficiency,the patient requires periodic infusion of genetically engineered lymphocytes because:

If $\frac{x^2}{a} + \frac{2xy}{h} + \frac{y^2}{b} = 0$ represents a pair of straight lines such that the slope of one of the lines is twice the other,then $\frac{ab}{h^2} =$

The work function of a metallic surface is $5.01 \ eV$. Photo-electrons are emitted when light of wavelength $2000 \ \mathring{A}$ falls on it. The potential difference applied to stop the fastest photo-electrons is .............. $V$ $[h = 4.14 \times 10^{-15} \ eV \cdot s]$.