Question

chem help needed - just please explain these concepts

10.0 grams of sodium metal react with 60.0 grams of copper (II) sulfate.
1. Write the balanced reaction with the correct products. (not sure how to do this)

2. Identify the reaction type (single replacement, double replacement, synthesis, decomposition or combustion).

3. What is the limiting reactant? (I really don't understand how to find this... I know I have to use stoichiometry but that whole concept is very confusing to me)

4. What is the theoretical yield of copper metal (in grams)?

5. What is the percent yield if 9.75 grams of copper metal are actually produced?

This question is from a study guide but im going to use this as like reference for future questions like this.

Answer 1

1. you have to know how to write the equation for copper sulfate and sodium

sodium is easy just Na from the p-table
copper sulfate is made from a copper (II) ion and a sulfate polyatomic anion (SO4^(2-))
Copper has a +2 charge, sulfate has a -2 charge so just
CuSO4

Na + CuSO4 ---> NaSO4 + Cu

2. compare the reaction to this chart and see which one is the best fit. remember you are looking for the pattern of which ion gets displaced.

Answer 2

3. you need to convert both reactants to moles and use the equation to determine how many moles of products each reactant produces. the smaller # is the limiting reactant

4. use the limiting reactant, convert g reactant--> moles product --> grams copper metal product

5. percent yield = (actual yield)/(theoretical yield) * 100%

the theoretical yield would be whatever you get from #4, the actual yield is 9.75

Answer 3

thank you... and do you happen to know how to do stoichiometry? if you do can you explain how to do it?

Answer 4

I set up a grid like this

Answer 5

put the unit I want to convert at the top left

Answer 6

then the next cell over gets the conversion factor that lets me convert to the next unit. in this case I can use (1 mol C / (12g C) to convert grams to moles

Answer 7

then I repeat the process until I end at the unit I need

Answer 8

what do you mean by moles of C?

Answer 9

1 mole of Carbon = 12 g C
this is a conversion factor that can let you go from moles of C to grams, or the other way around

I'm just using Carbon (C) as an example

Answer 10

still there?

you do know what a mole is right?

Answer 11

okay sorry im coming back to this just now..
okay i think I get what you are saying about the limiting reactant. What about the actual yield? how was it 9.75 in this case?