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A compound is found to contain 37.21% carbon, 7.75% hydrogen and 55.04% chlorine. What is it's empirical formula?

Carbon: 37.21/12= 3.1Hydrogen:7.75/1=7.75Chlorine: 55.04/35.5=1.55Ratio:c:H:Cl3.1:7.75:1.552:5:1Therefore empirical formula= C₂H₅Cl

Answered by Lucy P. • Chemistry tutor

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Expand the following expression and simplify: (3x+2)(4x+5)

12x² + 15x + 8x + 10 = 12x² + 23x + 10

Answered by Priscilla D. • Maths tutor

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A car depreciates at 8% per year. The initial price of the car is £25,000. How much will the car be worth after 4 years? After how many years will the car be worth less than £14,000?

This problem is all about compound interest except this time the value is going down not up. To increase a value by 8% you would multiply it by 1.08 as 8% is 0.08 (1+0.08). To decrease a value however you...

Answered by Hannah T. • Maths tutor

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The formula v = u +at gives the final velocity of an object as it accelerates. If v= 35, a=4 and t=5 then find u

First off, you would start by substituting in the numbers that you already know.
Therefore you get: 35 = u + (4 x 5)
Remembering BODMAS you would then look at the equation and solve the bracket...

Answered by Hannah G. • Maths tutor

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What was the significance of President Reagan in ending the Cold War?

The Triumphalist school of historical thought will argue that it was President Reagan's policies that forced the end of the Cold War. His massive increase in defence spending (about a 50% increase in the ...

Answered by Ruby K. • History tutor

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