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a) Complete the balanced symbol equations: (2 marks) H2SO4 + NaOH  HCl + Mg(OH)2 

H 2 SO 4 + 2NaOH --> 2H 2 O + Na 2 SO 4 2HCl + Mg(OH) 2 --> 2H 2 O + MgCl 2
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Answered by Claire P. • Chemistry tutor
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c) Sharon is organising an event. The tickets cost 12 pounds each. Sharon paid 200 pounds for the cost of the event. How many tickets will Sharon have to sell to make a profit? (2 marks)

Divide the cost of the event by the cost of the tickets to find how many tickets are required to break even 200/12 = 16.67 17 tickets would need to be sold to make any profit.
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Answered by Claire P. • Maths tutor
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a) Solve 6x + 13 =2x +5 (2 marks) b) Expand and simplify (q + 7)(q - 3) (2 Marks)

a) 6x+8=2x, 8=-4x, x=-2 b) q 2 + 7q -3q - 21, q 2 + 4q - 21
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Answered by Claire P. • Maths tutor
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A compound being analysed has the percentage composition by mass Ca = 13.9%, W = 63.9%, O = 22.2%. Calculate the empirical formula of this compound

Using rows to represent mathematical operations and a column for each compound we can draw ourselves a table: Ca W O % 13.9 63.9 22.2 Atomic Mass (Ar) 40 184 16 % / (Ar) 0.348 0.347 1.43 Ratio 1 : 1 : 4 This...
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Answered by Haydn D. • Chemistry tutor
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How do I sketch a quadratic function on graph paper?

First you need to draw a set of axis and choose a sensible scale, This is detrmined by parts of the equation such as the x and y intercept. Then what we need to do is to make a table of values. We can do X f...
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Answered by Jacob B. • Maths tutor
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