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3.786g of hydrated zinc sulphate, ZnSO4•xH2O, is heated to remove all water of crystallisation. The mass of anhydrous ZnSO4 formed is 2.122g. What is the formula of the hydrated zinc sulphate?

Water of crystallisation describes water molecules that are bonded into a crystalline structure of a compound. By knowing the mass of the hydrated salt (3.786g) and of the anhydrous salt (2.122g) it is possi...
CF
Answered by Claire F. • Chemistry tutor
11489 Views

The standard enthalpy of formation of glucose is -1273.3kJ/mol, and for carbon dioxide it is -393.5kJ/mol, and for water -285.8 kJ/mol. What is the standard enthalpy of combustion of glucose, C6H12O6?

The reaction equation has the form C 6 H 12 O 6 + x O 2 -> y CO 2 + z H 2 O. Balancing carbons, y = 6. Balancing hydrogens, z =6, so by balancing oxygen atoms, x = 6. Then we use a Hess's law cycle ( to b...
AC
Answered by Amber C. • Chemistry tutor
44638 Views

How does the reactivity change down Group 1 elements, and why?

The reactivity increases. Group 1 are the alkali metals so they react by losing their valence electrons. Caesium is more reactive because it gives up its electrons more readily. It has more inner shells so i...
EH
Answered by Emily H. • Chemistry tutor
3666 Views

Name and draw the mechanism where bromoethane reacts with NaOH to form ethanol.

Mechanism: Nucleophilic Substitution Electronegativity is the ability of an atom to attract a bonding pair of electrons. As bromine is more electronegative than carbon, the C-Br bond is polar, meaning the el...
Answered by • Chemistry tutor
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By comparing the forces involved, explain why hydrogen iodide (HI) would have a higher boiling point than hydrogen bromide (HBr)?

stronger van der waal bonds because iodide ion (I-) has a larger electron cloud so more polarisable so istantaneouos dipoles happen more often and more strongly, so more energy is needed to overcome these bo...
MW
Answered by Maddie W. • Chemistry tutor
9245 Views