JC1 Challenge 3

What is present in all viruses, all prokaryotes and all eukaryotes?

• ribose

• deoxyribose

• cytosine

• thymine

Four reactions of the type shown are studied at the same temperature.

X (g) + Y (g) → Z (g)

Which is the correct reaction pathway diagram for the reaction that would proceed most rapidly and with the highest yield?

• 
• 
• 
• 

A 10 cm beam is pivoted at its centre. Equal and opposite forces of 10 N pull the ends of the beam, creating a couple as shown.

What magnitude is the torque of the couple?

• 0.25 Nm

• 0.50 Nm

• 0.87 Nm

• 1.0 Nm

The table shows some steps that can be made in carrying out the Benedict’s test.

Which combination of steps is required to carry out a semi-quantitative test on a reducing sugar solution?

• A

• B

• C

• D

In which pair do both atoms have one electron only in an s orbital in their ground states?

• Ca, Sc

• Cu, Be

• H, He

• Li, Cr

1. A stone of weight 4.0 N earth’s gravitational field is moved from P to Q and then to R along the path shown.

2. How much potential energy does the stone gain?

• 120 J

• 200 J

• 280 J

• 200 J

The diagrams show three examples of different bonds.

Which bonds hold the secondary structure of proteins together?

• 1, 2, and 3

• 1 and 3 only

• 1 only

• 2 and 3 only

Which salt is produced by adding aqueous ammonia to aqueous sulphur dioxide until just alkaline?

• NH₄SO₃

• NH₄SO₄

• (NH₄)₂SO₃

• (NH₄)₂SO₄

What is the unit of Young modulus?

• Nm^-2

• Nm

• Nm^-1

• Nm²

1. Which statement correctly explains why blood plasma can be maintained at a stable

temperature?

• It has a low specific heat capacity.

• It has a high specific heat capacity.

• It has a low latent heat of vaporisation.

• It has a high latent heat of vaporisation.