Question

Indicate whether each statement is true or false.

1. When draining liquid from a pipet to a container, it is best to hold the tip of the pipet to the side of the container. True or False

2. When drawing liquid into the pipet, the tip of the pipet must be kept below the surface of the water to avoid drawing air into the pipet. True or False

3. The Volume of the liquid in a pipet should be measured by the location of the Top of the liquid meniscus. True or False

4. When measuring liquid from a pipet labeled as TD, allow liquid to drain but do not empty the pipet by squeezing on the bulb True or False

Answer 1

[1]

It is true. The liquid is pipet out by holding the tip to the side surface wall of the container. So, drop stuck with tip on pipet is also comes out.

[2]

yes, it's true. The bubbles in the pipet vary the volume. So, pipet must be kept below the surface of the sample.

[3]

False. No, it's not always true or false. there are two types of meniscus curve. concave and convex.

Concave curve generates when liquid stick to the surface wall. when the concave curve generate we should measure the bottom layer of the curve. in most of liquid and water concave curve generates.

Convex curve generates when liquid rippled to the surface wall. then we should measure the upper layer.

[4] True

There are two types of mark on the pipet TD & TC

TD = to deliver & TC = to contain