The acid that is used to remove rust is?
boric
hydrochloric
trioxonitrate (V)
tetraoxosulphate (VI)
Correct answer is B
No explanation has been provided for this answer.
Carbon (II) oxide is considered dangerous if inhaled mainly because it?
can cause injury to the nervous system
competes with oxygen in the blood
competes with carbon (IV) oxide in the blood
can cause lung cancer
Correct answer is B
Carbon monoxide is harmful when breathed because it displaces oxygen in the blood and deprives the heart, brain and other vital organs of oxygen.
Coffee stains can best be removed by?
Kerosine
turpentine
a solution of borax in water
ammonia solution
Correct answer is C
Borax solution refers to sodium borax in water. it is used for cleaning purposes. borax is mildly alkaline and can help break down acidic stains, such as those from coffee
4.00
2.50
0.40
0.25
Correct answer is B
Solubility = \(\frac{\text{number of moles of solution}}{\text{vol of solution}}\)
100g of water = 100 cm\(^3\) = 0.1 dm\(^3\).
CuSO\(_4\) = 160 g/mol
No of moles of CuSO\(_4\) in 40g = \(\frac{40}{160}\)
= 0.25 mol.
Solubility = \(\frac{0.25}{0.1}\)
= 2.5 moldm\(^{-3}\).
Substance employed as drying agents are usually?
amphoteric
hygroscopic
efflorescent
acidic
Correct answer is B
No explanation has been provided for this answer.