1. wirefree

37
Question: 2.0 g of a mixture of Na2CO3 and NaHCO3 was heated when its weight reduced to 1.876 g. Determine the percentage composition of the mixture.

Attempt: Here is my attempt:

Problem: My answers do not match those of the text. More critically, the procedure I've adopted is itself inconsistent with that outlined in the text: the "its" in the first line of the problem statement is interpreted in the text as the mass of Na2O alone, whereas I am considering it to be the combined mass of the products (see first 2 lines - chemical reactions - of my attempt above).

Whose interpretation is correct?

Would appreciate some thoughts.

Best regards,
wirefree

Last edited: Aug 5, 2014
2. wirefree

37
For those discouraged to answer, I've removed links to images in my original post and inserted the appropriate image instead.

Regards,
wirefree

Last edited: Aug 5, 2014

Staff: Mentor

I don't get the light blue comment nor the equation after it.

Think again: what are the reactions taking place and what are the final products?

Last edited: Aug 5, 2014
1 person likes this.
4. epenguin

2,125
Not gone through. Unfortunate fact: someone else's arithmetic is as attracting as someone else's unmade bed. Despite your colouring etc. is thoughtful and helpful and as good as it gets!

However I noticed that in your first equation Na2CO3 went to Na2O. In the second you show Na2CO3 as a product that just stays there. Why wouldn't that also go to Na2O ?

Last edited: Aug 5, 2014