Give an example of a double displacement reaction other than the one given in activity 1.10.
Pb(NO3)2 (aq) + 2KI (aq) → PbI2 (s) + 2KNO3 (aq)
Lead Nitrate Potassium Iodide Lead Iodide Potassium Nitrate
When the aqueous solution of lead Nitrate is mixed with potassium Iodide, we obtain a precipitate of lead iodide and a solution of potassium nitrate. In double ddisplacement reaction their is exchange of ions between the reactant. In this reaction, the cation Pb2+ and K+ exchange their anions NO3- and I- to give new substance PbI2 and KNO3.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
Outline a project which aims to find the dominant coat colour in dogs.
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
How is the sex of the child determined in human beings?
Calculate the number of electrons constituting one coulomb of charge.
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
What is an homologous series? Explain with an example.
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Why is variation beneficial to the species but not necessarily for the individual?
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.
How is the sex of the child determined in human beings?
Explain the formation of scum when hard water is treated with soap.
Which of the following are environment-friendly practices?
(a) Carrying cloth-bags to put purchases in while shopping
(b) Switching off unnecessary lights and fans
(c) Walking to school instead of getting your mother to drop you on her scooter
(d) All of the above
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
Draw the structure of a neuron and explain its function.
Choose the correct option.
A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each
(a) two revolutions (b) one revolution
(c) half revolution (d) one-fourth revolution
Outline a project which aims to find the dominant coat colour in dogs.
Translate the following statements into chemical equations and then balance them.
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.