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25.00cm3 of sodium hydroxide was pipetted into a conical flask. It was titrated against 0.10mol/dm3 hydrochloric acid. The mean volume of acid needed was 24.00cm3. Calculate the concentration of sodium hydroxide used in the titration.

First write out the chemical equation: ​​​​​​ HCl + NaOH -> NaCl + H 2 0 Next construct a table with the information we have and in what units. Next write out what calculation triangle we need: Number of ...
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Answered by Matthew B. • Chemistry tutor
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Amy has cystic fibrosis which is caused by a recessive allele. Her partner is heterozygous for cystic fibrosis. What is the chance that her future child has cystic fibrosis?

Alleles are different forms of a gene which can become mutated to cause different characteristics or diseases. They can be dominant (usually denonimated by a captial letter H) or recessive (usually denominat...
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Answered by Rebecca M. • Biology tutor
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How do you expand (2x+9)^2?

(2x+9) 2 = (2x+9)(2x+9) Use FOIL to expand these brackets: First - ( 2x +9)( 2x +9) --> 4x 2 Outside - ( 2x +9)(2x+ 9 ) --> 4x 2 + 18x Inside - (2x +9 )( 2x +9) --> 4x 2 + 18x + 18x Last - (2x +9 )(...
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Answered by Alec M. • Maths tutor
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What is the difference between exothermic and endothermic reactions?

The first law of thermodynamics states that energy can neither be created nor destroyed. Energy has to be used when breaking bonds, yet is formed when making bonds. This means that there will be an overall n...
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Answered by Alec M. • Chemistry tutor
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How may cells be specialised to their function?

Despite animal cells all having a nucleus (for genetic information storage and reproduction), a cytoplasm (for structure), mitochondria (for aerobic respiration), ribosomes (for protein synthesis) and a cell...
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Answered by Alec M. • Biology tutor
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