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Chemistry
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25cm3 NaOH was titrated with 0.05mol dm-3 HCl. 21.5m3 of HCl neutralised 25cm3 of NaOH. What is the concentration of NaOH in mol dm-3?

NaOH + HCl --> NaCl + H2O 1 : 1 : 1 moles (mol) = concentration (mol dm-3) x volume (dm3)

Answered by Britta A. Chemistry tutor
4296 Views

Name Group 0 in the periodic table. What is the tree in boiling points and why?

The Noble GasesThe boiling points increase as you go down the group. This is because the atoms get larger and the intermolecular forces become more numerous and stronger hence more energy is needed to bre...

Answered by Ellie B. Chemistry tutor
1765 Views

Bethan prepared some ethoxyethane (line 6) by reacting ethanol with concentrated sulfuric acid. She used 69g of ethanol (Mr=46) and obtained a 45% yield of ethoxyethane (Mr=74). Calculate the mass of ethoxyethane obtained.

  1. Equation from line 6 is: 2 (ethanol) -------> 1 (ethoxyethane)
    2. The ratio of reaction is 2:1. This is the ratio of moles not mass, i.e., 2 moles of ethanol give 1 ...
Answered by Shreyasi D. Chemistry tutor
1821 Views

Give the name of the monomer used to make poly(chloroethene). And describe how monomer molecules form polymer molecules.

  1. Briefly explain the etymology of hydrocarbon names and how polymers are named. The answer is therfore, chloroethene.
    2. Draw a structure for chloroethene and show in diagram how chloroethene p...
Answered by Shreyasi D. Chemistry tutor
11322 Views

Explain the trends in electronegativity in the periodic table

As you go across the period from left to right (excluding noble gases), electronegativity increases. This is because the nuclear charge increases (Atomic Number/number of protons) and atomic radius decrea...

Answered by Anika P. Chemistry tutor
2610 Views

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