+7 to +3
+6 to +3
+5 to +3
-2 to +3
Correct answer is A
No explanation has been provided for this answer.
0.40 kg
0.20 kg
0.06 kg
0.04 kg
Correct answer is C
In the reaction: \(SnO_{2} + 2CO\)
From the equation above
2(12 g) carbon = 151 g \(SnO_{2}\)
24 g carbon =151 g \(SnO_{2}\)
= 0.302 kg \(SnO_{2}\) = 24/151g χ 0.0302 kg carbon = 0.048 kg carbon
Mass of coke is required not mass of carbon,so it is (0.048\(\times\)100)\(\div\)80 = 0.06
Which of the following is a physical change?
The bubbling of chlorine into water
The bubbling of chlorine into a jar contanining hydrogen
The dissolution of sodium chloride in water
The passing of steam over heated iron
Correct answer is C
No explanation has been provided for this answer.
Which of the following statements is true?
Metals conduct electricity while non-metals do not
Metals have high density, non-metals have low density
Metals form basic oxides, non-metals form acidic oxides
In the electro chemical series, metals are above hydrogen while non-metals are below hydrogen
Metals lose elections while non-metals gain electron during chemical reactions
Correct answer is E
- Chemical reactions in which electrons are transferred are called oxidation-reduction, or redox, reactions. Oxidation is the loss of electrons. Reduction is the gain of electrons. Oxidation and reduction always occur together, even though they can be written as separate chemical equations. -The most common reducing agents are metals, for they tend to lose electrons in their reactions with nonmetals. Option E is most appropriate.
Which of the following statements is an exception in the assumptions of the kinetic theory of gases?
Gases are composed of many elastic particles
The particles are of negligible size
The particles are in constant random motion
The particles are of negligible mass
The particles collide with each other
Correct answer is D
No explanation has been provided for this answer.