Students' joy as GCSE chemistry exam answers its own question

An AQA GCSE exam paper asked and answered its own question on the chemical components of limestone Credit: PA

GCSE students who took their chemistry exam yesterday were surprised to find the answer to one of the questions was given away in the same test.

The AQA paper asked students to complete a statement about the chemical component of limestone, but answered the teaser itself a few questions on:

Many delighted students expressed their joy over the easy win on Twitter:

While others feared that the blunder may push up the minimum marks needed for each grade:

AQA apologised, but admitted that it was aware of the error before the exams were given to students.

A spokeswoman said: "The answer to Question 2(a)(i), asked students to complete the sentence ‘The main compound in limestone is calcium____’. In Question 5, part of the question states : ‘Limestone is mainly calcium carbonate’.

"As part of our ongoing quality control checks we noticed that an answer to a one-mark question was given in a longer question later on in the paper. This shouldn’t have happened, and we’re sorry it did.

Quiz: Could you pass GCSE Maths?

"As the papers had already been sent out to schools and colleges, we took the view (and informed our regulator, Ofqual) that it was better to leave both questions in than cause unnecessary stress and confusion to students right at the start of the exam.

"We’ll make sure it doesn’t affect students’ grades, but schools can get in touch if they have concerns."

Last week #Edexcelmaths was trending on Twitter after students were left flummoxed by a particularly tough question:

More: GCSE maths SHOULD be challenging, argues Rachel Riley, after thousands of students complain online