288. Quick lime (or caustic lime)
A. is obtained by the calcination of pure lime stone
B. has great affinity to moisture
C. is amorphous
D. All the above.

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289. For slaking of 10 kg of CaO, the theoretical amount of water is
A. 2.2 kg
B. 1.5 kg
C. 3.2 kg
D. None of these.

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290. Which one of the following is an air binding material ?
A. Gypsum
B. Acid-resistant cement
C. Quick lime
D. All of these.

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291. Pick up the correct statement from the following :
A. The lime in excess makes the cement unsound and causes the cement to expand and disintegrate
B. The silica in excess makes the cement stronger but its setting time also increases
C. The excess amount of alumina weakens the cement
D. All the above.

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292. The cement becomes unsound by the presence of excess
A. sulphur
B. magnesia
C. lime
D. All of these.

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293.  Pick up the compound responsible for early strength of cement from the following :
A. Tetra-calcium alumino-ferrite
B. Tricalcium silicate
C. Tricalcium aluminate
D. Dicalcium silicate.

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294. In the cement the compound quickest to react with water, is
A. Tricalcium aluminate
B. Tetra-calcium aluxnino-ferrite
C. Tricalcium silicate
D. Dicalcium silicate.

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