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Chemistry Questions

Question 226:

Allotropes are elements having?

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A Different physical but the same chemical properties
B Different chemical but the same physical properties
C The same chemical and physical properties
D Different atomic structure
E The same position in the periodic table

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Question 227:

A polymerization reaction is one in which?

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A Small molecules form giant molecules
B Atoms form molecules
C Giant molecules form small molecules
D Molecules form volatile compounds
E A molecule rearranges itself

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Question 228:

Which of the following is the electronic configuration of sodium? <br/>(Atomic number of Na = 11)

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A 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>2</sup>
B 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>2</sup> 3p1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>1</sup>
C 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>1</sup>
D 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 3s<sup style='font-size: smaller;'>°</sup>
E 1s<sup style='font-size: smaller;'>2</sup> 2s<sup style='font-size: smaller;'>2</sup>2p<sup style='font-size: smaller;'>6</sup> 4s<sup style='font-size: smaller;'>1</sup>

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Question 229:

In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?

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A One atom of hydrogen reacts with two atoms of oxygen to give one molecule of water
B Two atoms of hydrogen react with two atoms of oxygen to give two molecules of water
C One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of water
D One molecule of hydrogen reaccts with two molecules of oxygen to give three molecules of water
E One molecule of oxygen reacts with two molecules of hydrogen to give two molecules of water

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Question 230:

Na<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub> + 2HCI â†’ 2NaCI + H<sub style='font-size: smaller;'>2</sub>O + CO<sub style='font-size: smaller;'>2</sub>. Using the above equation, what volume of carbondioxide, measured at s.t.p is liberated when 53g of sodium carbonate is dissolved in hydrochloric acid?<br/>(1 mole of gas occupies 22.4 dm<sup style='font-size: smaller;'>3</sup> at s.t.p)<br/>(Na = 23, C = 12, O = 16)

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A 44.8 dm<sup style='font-size: smaller;'>3</sup>
B 11.2 dm<sup style='font-size: smaller;'>3</sup>
C 100.1 dm<sup style='font-size: smaller;'>3</sup>
D 3.0 dm<sup style='font-size: smaller;'>3</sup>
E 22.4 dm<sup style='font-size: smaller;'>3</sup>

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