°API gravity of water at N.T.P. is about__________________?

Related Mcqs:

1. Specific gravity on API scale is given by the relation (where, G = specific gravity at 15.5°C) ?

   A. °API = 200(G – 1)
   B. °API = (141.5/G) – 131.5
   C. °API = (140/G) – 130
   D. °API = 145 – (145/G)

2. Which of the following expressions defines the Baume gravity scale for liquids lighter than water ?

   A. °Be = (140/G) – 130
   B. °Be = 200(G-1)
   C. °Be = 145 – (145/G)
   D. °Be = (400/G) – 400

3. Which of the following expressions defines the Baume gravity scale for liquids heavier than water ?

   A. (141.5/G) – 131.5
   B. 145 – (145/G)
   C. 200 (G-1)
   D. (400/G) – 400

4. Which of the following gravity scales is used exclusively for liquids heavier than water ?

   A. Baume scale
   B. Twaddell scale
   C. API scale
   D. None of these

5. A vessel of volume 1000 m3 contains air which is saturated with water vapour. The total pressure and temperature are 100 kPa and 20°C respectively. Assuming that the vapour pressure of water at 20°C is 2.34 kPa, the amount of water vapour (in kg) in the vessel is approximately ?

   A. 17
   B. 20
   C. 25
   D. 34

6. Assume that benzene is insoluble in water. The normal boiling points of benzene and water are 80.1 and 100°C respectively. At a pressure of 1 atm, the boiling point of a mixture of benzene and water is__________________?

   A. 80.1°C
   B. Less than 80.1°C
   C. 100°C
   D. Greater than 80.1°C but less than 100°C

7. The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. The temperature at which the above mixture will exert a pressure of one standard atm. is___________________?

   A. Less than 100°C
   B. 100°C
   C. Between 100 and 110°C
   D. 110.6°C

8. At 100°C, water and methylcyclohexane both have vapour pressures of 1 atm. Also at 100°C, the latent heats of vaporisation of these compounds are 40.63 kJ/mole for water and 31.55 kJ/mole for methylcyclohexane. The vapour pressure of water at 150°C is 4.69 atm. At 150°C, the vapour pressure of methylcyclohexane would be expected to be_________________?

   A. Significantly less than 4.69 atm
   B. Nearly equal to 4.69 atm
   C. Significantly more than 4.69 atm
   D. Indeterminate due to lack of data

9. Saturated solution of benzene in water is in equilibrium with a mixture of air and vapours of benzene and water at room temperature and pressure. Mole fraction of benzene in liquid is xB and the vapour pressures of benzene and water at these conditions are pv B and pv w respectively. The partial pressure of benzene in air-vapour mixture is_________________?

   A. PvB
   B. xB.PvB
   C. (Patm – Pvw)xB
   D. xB.Patm

10. One of the specific gravity scales is “Brix” (used specifically for sugar solution). It is defined as ______________?

    A. Brix = (400/G) – 400
    B. Brix = 200 (G-1)
    C. Brix = 145 – (145/G)
    D. None of these