Chemistry

What is used as drying agent:

Calcium sulfate

Which polymer has H bonding between chains: Kevlar, polythene, PVS, terylene

Kevlar

What is used as inert electrode

platinum

Why does polyamide Q have an environmental benefit over polyalkene P

NH4VO3 reaction with heat

2 NH4VO3 —> V2O5 + H2O + 2NH3

Reagent for [Fe(H2O)6]3+ to [Fe(H2O)6]2+

Zinc in acid

Why is Copper(I) iodide white

Full 3d (sub)shell

No (d-d) transitions possible so cannot absorb visible/white light

NaBr and H2SO4 reaction to form SO2

Purifying crystal from solution process

Why use KCN instead of HCN in reaction

KCN dissociates more to form greater[CN-] than HCN, as HCN weak acid: and HCN toxic gas

What is slat bridge made of

Unreactive (with cells) ionic compound, so eg. sodium nitrate.

Increasing concentration in electrochemical cell: emf…

EMF more positive, less electrons produced

Increasing pressure in electrochemical cell: emf…

EMF more negative, more electrons produced

Why does fuel cell not need to be recharged

Reactants supplied continuously in fuel cell

why is electron impact not used in ionising protien in mass spectrometer

So protein doesnt fragment with electron impact

Mg + steam reaction

Mg + H2O —> MgO + H2, bright white light

Why is pipette washed with used solution

So water doesnt dilute the solution. so conc Ba(OH)2 known