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What is the standard enthalpy change of formation and how does it differ from the standard enthalpy change of reaction?

The enthalpy change of formation is the enthalpy change when 1 mole of a compound is formed from its constituent elements in their standard states. Meanwhile the enthalpy change of reaction is the enthalpy c...
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Answered by Abigail J. • Chemistry tutor
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What is the use of membranes within the cell?

Membranes within the cell are used in compartmentalisation for numerous reasons- one being to allow processes to occur separately in different organelles without interacting and affecting other processes, wh...
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Answered by Abigail J. • Biology tutor
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What is a standard electrode potential?

The EMF voltage produced when a half cell is connected to a standard hydrogen half cell under standard conditions. Standard conditions are 298 Kelvin, 100 kPa, and all solutions must be in 1 moldm -3 molarity.
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Answered by Abigail J. • Chemistry tutor
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How do you make a buffer?

A buffer is a mix of an excess of weak acid and its salt. Buffers can be made in two ways- by mixing the weak acid with its salt or by partially neutralising the weak acid with base. 1- Making buffers by mix...
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Answered by Abigail J. • Chemistry tutor
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Fahima buys 2 packets of bread rolls costing £1.50 for each packet 1 bottle of ketchup costing £1.60 3 packets of sausages Fahima pays with a £10 note. She gets 30p change. Fahima works out that one packet of sausages costs £2.30 Is Fahima right?

Let's denote the price of sausages as S as it's the only unknown.Let's use simple algebra to solve this.To find the total price of all of the items she purchased ( i.e. the value), we multiply price by the q...
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Answered by Maria C. • Maths tutor
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