Carboxylic acids react with alcohols to make esters. A small amount of concentrated sulfuric acid is used as a catalyst. Consider the following ester: What is the name of the…

The diagram shows changes in the structure of the uterus lining during the menstrual cycle in a healthy female. Two regions are labelled Q and R. S shows when ovulation…

Five congruent small rectangles are joined, as shown, to form one large rectangle. The large rectangle is mathematically similar to each of the small rectangles. For each small rectangle, find…

A solid cuboid has dimensions 0.20 m × 0.10 m × 0.10 m and density 2000 kg m–3. What pressure is exerted by the weight of the cuboid when it…

An inorganic salt was analysed to determine its composition. The compound gave a lilac flame in a flame test. After dissolving in water and adding sodium hydroxide solution, a green…

A mature active cell in a healthy human has the following features: a cell membrane no nuclear DNA molecules that bind with oxygen.Which of the following statements about this cell…

What is the mean of 12 , 27 and 147 ? Answer: 8) B /12 = √√2 x 2 x 3 = 2√3√27 = 3x3x3 = 3√3147 = √7x7x3 =…

A radiation detector on a laboratory bench is switched on when there are no radioactive samples in the laboratory. The count rate displayed by the detector is 24 counts per…

The industrial manufacture of ethanol from ethene is a catalysed reversible reaction. The equation for this reaction is:C2H4(g) + H2O(g)֖ C2H5OH(g) ΔH = – 46 kJ mol –1Which of the…

The browning of fruit involves enzymes. The time taken for slices of apple kept in different solutions to turn brown is shown in the table. The effect of pH and…