Average speed = total distance travelled ÷ total time taken

AS = (75km + 68km) ÷ (1hr + 2hr)

As = 143km ÷ 3hr

AS = 47.66667 km/hr

AS = 47.7 km/hr (3sf)

8 0

3 years ago

When looking at the chemical symbol, the charge of the ion is displayed as the

Black_prince [1.1K]

Answer:

superscript

Explanation:

When looking at the chemical symbol, the charge of the ion is displayed as the Superscript. This is because the charge of ions is usually written up on the chemical symbol while the atom/molecule is usually written down the chemical symbol. The superscript refers to what is written up on the formula while the subscript is written down on the formula.

An example is H2O . The 2 present represents two molecule of oxygen and its written as the subscript while Fe2+ in which the 2+ is written up is known as the superscript.

6 0

4 years ago

Which of the given will facilitate a normal Diels–Alder reaction?

babymother [125]

Answer:

Explanation:

- The rate of the Diels-Alder is orders of magnitude faster if there is an electron-withdrawing group on the dienophile. For example, replacing a hydrogen on ethene with the electron-withdrawing group CN results in about a 10^5 increase in the reaction rate.

- Other common electron withdrawing functional groups that will accelerate the Diels Alder reaction of dienophiles include aldehydes, ketones, and esters.

- In short, any functional group conjugated with the pi bond which can act as a pi acceptor will accelerate a Diels-Alder reaction with a typical diene.

- See attachment for graphical explanation.

7 0

3 years ago