Top answers

State the reagents and conditions for the formation of an aldehyde, starting from a primary-alcohol.

Answer: Heat with acidified potassium dichromate (IV), distilling off the aldehyde as it forms. Explanation: To form an aldehyde from an alcohol the alcohol group must be oxidised. To do this we use potassiu...
TO
Answered by Tom O. • Chemistry tutor
6043 Views

Which verbs use etre and which use avoir in the past tense, and why?

The past tense is constructed in 2 parts: 1) the auxiliary 'avoir' or 'être' is conjugated in the present + 2) the past participle of the verb. The majority of verbs use avoir in the past tense (e.g. j'ai ma...
FW
Answered by Flick W. • French tutor
3882 Views

Describe how water moves from roots to leaves (3 marks)

Via the process of transpiration:Water is evaporated from the leaves in the canopy. Due to capillary action, this causes more water to move up the plant through the xylem vessels to replace the water as it i...
LN
Answered by Laura N. • Biology tutor
5570 Views

y = e^(e^x). Show that the curve has no maxima or minima for any real number.

dy/dx = (e^x)*(e^(e^x)) which is never equal to zero so it does not have any maximum or minimum.
PM
Answered by Pablo M. • Maths tutor
1702 Views

Ms Henderson has two jars of sweets. The jars contain the same number of sweets in total. 25% of the sweets in Jar A are mint. Two fifths of the sweets in Jar B are mint. There are 10 mint sweets in Jar A, how many mint sweets are there in Jar B?

For this question we should be familiar with percentages and their equivalents in fraction. Since they have the same number of sweets, we calculate first the total number of sweets there is in the jars and w...
PM
Answered by Pablo M. • Maths tutor
3648 Views