1948
1956
1971
1963
Correct answer is A
Apartheid officially began in South Africa in 1948. It was a system of institutionalized racial segregation and discrimination that lasted until the early 1990s. The National Party, which came to power in 1948, formalized and expanded segregationist laws into the apartheid system.
passed over heated copper (II) oxide
bubbled through concentrated tetraoxosulphate (IV) acid
bubbled through sodium hydroxide solution
bubbled through water
Correct answer is C
No explanation has been provided for this answer.
Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating?
Silver and trioxonitrate (V)
Sodium trioxonitrate (V)
Calcium trioxonitrate (V)
Lithium trioxonitrate (V)
Correct answer is A
No explanation has been provided for this answer.
The Kanem-Borno Empire prospered due to its control over
Ivory trade
Salt trade
Gold trade
Copper trade
Correct answer is B
The Kanem-Borno Empire prospered due to its control over the salt trade. The empire was strategically located on trans-Saharan trade routes, and it capitalized on this by controlling the trade of salt, a valuable commodity at the time.
Which of these gases can be dried with concentrated H2SO4?
HBr
H2S
NH3
SO2
Correct answer is D
In the preparation of \(SO_{2}\), we have the resultant reaction from heating the mixture of \(Na_{2}SO_{3}\) and \(HCl\) as:
\(Na_{2}SO_{{3}{(aq)}} + 2HCl_{(aq)} \to 2NaCl_{(aq)} + H_{2}O_{(l)} + SO_{{2}{(g)}}\)
Passing the gas evolved through conc. \(H_{2}SO_{4}\), we collect \(SO_{2}\) by DOWNWARD DELIVERY, leaving \(NaCl\) in the flask.