Density and Flow

Density of liquids and solids:

• changes a lot with changes in Temperature and Pressure

• does not change with changes in Temperature and Pressure

• changes slightly with change in Temperature and is not affected by Pressure

• changes slightly with change in Pressure and is not affected by Temperature

If a liquid has a specific gravity of 2.2, then its density is

• 2.2 kg/m³

• 2.2 g/cm³

• 2.2 lb_m/ft³

• 2.2 (dimensionless)

A certain oil has a specific gravity of 0.750. A 0.500 cubic meter sample of this oil has a mass of:

• 0.375 g

• 1.50 g

• 1.50 kg

• 0.375 kg

A sample is collected from a liquid stream. In 20 seconds, a volume of 15 L is collected. The volume flow rate is:

• 0.75 m³/s

• 45 L/min

• 300 L/s

• 1.33 m³/min

A rotameter must always be installed:

• horizontally in direction of flow

• vertically with upward flow

• vertically with downward flow

• horizontally in opposite direction of flow

An orifice flow meter measures flow rate indirectly by measuring:

• pressure drop

• change of velocity

• weight changes

• position of float

Volumetric flow rate V^. can be written in terms of cross-sectional area (A) and velocity (u) as:

• V^. = A÷u

• V^. = u÷A

• V^. = A×v

• V^. = A×v²

If two substances have the same specific gravity, but different densities then it means:

• the reference used for both was different

• there is a mistake in the calculation of the densities

• it is not possible

• they are measured at different locations where the value of g is different

If the density is 85 lb_m/ft³, then the weight of 0.5 ft³ of this substance is:

• 42.5 lb_f

• 170 lb_f

• 1367 lb_f

• 5469 lb_f

Solid zinc reacts with liquid hydrochloric acid to produce zinc chloride and hydrogen gas. The change can be classified as:

• physical change

• chemical change

• neither