Search our library of homework questions

Top answers

All subjects

All levels

Why is the long-run Phillips Curve vertical?

The Phillips Curve depicts the relationship between unemployment and inflation. Suppose the government pursues an expansionary policy (e.g. lower interest rates). Using the classical model of aggregate de...

Answered by Fin C. • Economics tutor

21199 Views

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 magnitud...

Answered by • Physics tutor

5830 Views

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...

Answered by Charlotte L. • Maths tutor

13538 Views

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 predictio...

Answered by Kieran R. • Chemistry tutor

7290 Views

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 ket...

Answered by Julie T. • Chemistry tutor

3751 Views