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What is the difference between Speed, Velocity and Acceleration?

Speed and Velocity are both measures of distance travelled in a given time and are therefore calculated using Speed=Distance/Time.Speed is a scalar quantity which means that it is quantified by a magnitude o...
Answered by • Physics tutor
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Prove by contradiction that there is an infinite number of prime numbers.

The 'by contradiction' tells us we need to assume the opposite to begin with: 1) Let's assume there is a finite number of prime numbers2) Let P be the largest prime number (the last one) 3) if we multiply al...
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Answered by Charlotte L. • Maths tutor
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Use the following data to explain why NaCl is soluble in water: ∆H = +31 kJmol-1, S(Na+(aq)) = 320.9 JK-1mol-1, S(Cl-(aq)) = 56.5 JK-1mol-1, S(NaCl(s)) = 72.1 JK-1mol-1 Are there any temperatures at which you would not expect NaCl to dissolve?

This is a nice simple calculation question which explores some basic thermodynamic principles and begins to apply them to simple reactions (in this case, solid salt dissolving in water) allowing predictions ...
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Answered by Kieran R. • Chemistry tutor
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How can one differentiate between the organic compounds propanal (CH3CH2CHO) and propanone (CH3COCH3)?

React a sample of each compound with Tollens reagent. The aldehyde (propanal) will be oxidised to a carboxylic acid (propanooic acid) and will form a silver mirror. No change will be observed with the ketone...
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Answered by Julie T. • Chemistry tutor
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What are the necessary conditions for a random variable to have a binomial distribution?

There can only be two possible outcomes, 'success' and 'fail' (e.g heads or tails) There is a fixed number of trialsThe probabilities of 'success' and 'fail' are constant and stay the same in each trial (e.g...
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Answered by Julie T. • Maths tutor
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