[papz]

3.
A mixture of MGS04 and CuSO4.7H20 is heated at 120(degrees C) until a mixture of the anhydrous compounds is produced. If 5.00g of the mixture gave 3.00g of the anhydrous compounds, calculate the percentage by mass of MGSO4.7H20 in the mixture.

4.
1 mole of a hydrocarbon formula CnH2n was burned completely in oxygen producing carbon dioxide and water vapour only. It requires 192g of oxygen. Work out the formula of the hydrocarbon.

5. When 15cm^3 of gaseous hydrocarbon was exploded with 60cm^3 of oxygen (an XS), the final volume was 45cm^3. This decreased by 15cm^3 on treatment with NaOH solution ( removes C02 ). What was the formula of the hydrocarbon (all measuremnets were made at room temp. and pressure, & water produced is liquid)

6.
A fertilser contains ammonuim sulphate and pottasuim sulphate. A samply of 1.455g of the fertilise was warmed with 25cm^3, 0.2moddm^-3 NaOH solution giving of ammonia gas. The remaining NaOH that was not used requireed 28.7cm^3 of 0.100moldm^-3 HCl acid for nuetrulisation. Calculate the % by mass of ammonuim sulphate in the sample.


I HAVE NO IDEA HOW TO DO THESE, HAVE YOU GOT SOLUTIONS?

[Karakth]

3.

Make sure you have written the question down correctly: did you mean MgSO₄.7H₂O and CuSO₄.7H₂O? Assume that all the mass lost is water.

4. & 5.

My teacher gave us the following equation. I haven't seen it around, but I'm sure it will help you:

C_xH_y + (x + y/4)O₂ --> xCO₂ + y/2H₂O

6.

As always, start by writing the equation. How do ammonium sulphate and potassium sulphate react with NaOH?

P.S. Sorry but no-one here will give you solutions, especially to homework questions...We cannot do your homework for you!

[mike]

I thought people were supposed to attempt the questions before posting so we could see what you have done?

[Karakth]

Indeed, I assumed the person did not know where to start.