user223679

Clue: For every one mole of SnO$_{2}$ you need two moles of Carbon. What is twice of 14g? That's the amount of Carbon you need.

I've posted a question or an answer, and I have received one or more downvotes. I am not really sure why I was down voted, or I think I know why, but I disagree. Why did this happen, and what should I do about it?

I am not sure if this comment about a suggestion on stackoverflow should be written here, but I do think so. I would recommend, if this is possible, when downvoting a question, to be mandatory for the downvoter, to write the reason why he/she downvoted. I think this should be much more helpful ...