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Only one question really bothered me, and that was the one in the VCU packet I think, where it said an aldehyde was a type of ketone. I'm pretty sure this isn't right. It was confusing enough that I didn't get it at the end of the question.

Judy Sucks a Lemon for Breakfast wrote:Only one question really bothered me, and that was the one in the VCU packet I think, where it said an aldehyde was a type of ketone. I'm pretty sure this isn't right. It was confusing enough that I didn't get it at the end of the question.

An aldehyde is a ketone where one of the R groups is H, so no.

EDIT: To be fair, that's only one way of describing it--the aldehyde:ketone relationship could be said to be primary:secondary, rather than one of types, if you're at the moment mostly interested in the fact that the aldehyde is terminal. But it's hard to say that an aldehyde isn't a type of ketone.

Crazy Andy Watkins wrote:

Judy Sucks a Lemon for Breakfast wrote:Only one question really bothered me, and that was the one in the VCU packet I think, where it said an aldehyde was a type of ketone. I'm pretty sure this isn't right. It was confusing enough that I didn't get it at the end of the question.

An aldehyde is a ketone where one of the R groups is H, so no.

EDIT: To be fair, that's only one way of describing it--the aldehyde:ketone relationship could be said to be primary:secondary, rather than one of types, if you're at the moment mostly interested in the fact that the aldehyde is terminal. But it's hard to say that an aldehyde isn't a type of ketone.

Whether correct or not, I agree that it was confusing. I think my classes just said "ketone = bonded to two carbons, aldehyde = bonded to one carbon and a hydrogen." I won't claim to know the most technically correct definition, but I think the question would be more clear if it said "class of carbonyl compound with one R group being just hydrogen" or something along those lines.

Crazy Andy Watkins wrote:

Judy Sucks a Lemon for Breakfast wrote:Only one question really bothered me, and that was the one in the VCU packet I think, where it said an aldehyde was a type of ketone. I'm pretty sure this isn't right. It was confusing enough that I didn't get it at the end of the question.

An aldehyde is a ketone where one of the R groups is H, so no.

EDIT: To be fair, that's only one way of describing it--the aldehyde:ketone relationship could be said to be primary:secondary, rather than one of types, if you're at the moment mostly interested in the fact that the aldehyde is terminal. But it's hard to say that an aldehyde isn't a type of ketone.

I think how you describe it makes sense, but pretty much everything I read about aldehydes never said they were a type of ketone, so it made the question harder to answer. Also, what makes it confusing is the fact that usually when you learn about those groups they're both just listed under carbonyl and nothing else.