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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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Would you expect a calcium ion to be bigger, smaller or the same size as a calcium atom? Give TWO reasons to explain your answer.

Calcuim is in group two which means when it forms an ion it will donate its two outer elections, this means a calcium ion will be smaller as it has one less shell of electrons.
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Answered by Urma C. • Chemistry tutor
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State and explain the effect of the following on the rate of a reaction: a) increasing temp b) increasing pressure c) increasing concentration of ONE reactant d) adding a catalyst. In each case state what will happen to the rate constant, k.

a) will increase greater collision energy so greater chance of activation energy being exceeded so greater fraction of successful collisions k increases b) will increase more particles per unit volume so col...
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Answered by Joseph P. • Chemistry tutor
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When you are given a table of half cells with values for electrode potentials, how do you find the strongest oxidising and reducing agent?

Possibly the easiest way to do this is by thinking about what the value of Electrode Potential means. The more positive the Electrode Potential, the greater the tendency of the species in the equation to be ...
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Answered by James S. • Chemistry tutor
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What is an acid and what is the difference between and strong and weak acid

An acid is a proton donor. The acid molecule may have one or more protons that it can lose depending on its structure, however generally the second proton is much less acidic (meaning that it is lost much le...
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Answered by Lea S. • Chemistry tutor
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