Q1:What effect would each of the following have on the...

Q1:What effect would each of the following have on the observed melting point and melting point range of a sample: (10 POINT a) Use of a thick-walled melting point tube b) Rapid heating c) Use of so much sample that the filled portion of the capillary tube extends considerably beyond the thermometer bulb d) Presence of solvent within the crystal e) Presence of piece of glass in the sample Q2: Why melting point are routinely used ?(2POINT Q3: Why and how the Thermometer calibration ? (4 point Q4: Draw the temperature composition diagram for the following data: (4 POINT melting point compound 130 Pure A 156 Pure B 112 A : 50% B 50% 140 A : 80% B 20% 126 A: 20% B 80%

Transcript

00:01 Hello student.

00:03 So in this question it is asked about the melting point right so first option it says if we use a thick vault melting point tube.

00:13 A thick volume melting point tube it may result in increase of the melting point of our sample.

00:22 It may increase the melting point of sample.

00:30 Next it says that if we do the rapid hitting see by heating rapidly rapid heating means that we are doing the heating process very in a very fast way right so rapid rapid heating it may get we don't get an accurate reading right we are doing the rapid heating so we don't get any accurate reading so we can say that suppose sub alternately if you do the melting point of the same to be around suppose 120 right so you can rapidly heat it to heat it to 100 right but then slow down to receive an accurate melting point read so but therefore we can say that rapid heating it do not get accurate reading we have to slow down this process to get the accurate reading right next c says that use of so much sample that the filled portion of capillary tube extends considerably beyond the thermometer bulb.

01:40 So we can say that we will get in this case a wrong reading.

01:47 We have the sample and it extends if the thermometer bulb, so we will get the wrong reading.

01:52 Why? remember this thing that thermometer measures the temperature at the bulb.

01:58 If your sample is above the bulb then the reading would not be the same.

02:04 So next is if some crystal is present there, some piece of glass is present in the sample or presence of solvent in the crystal.

02:15 So see, the presence of, we can say that something like glass that is insoluble impurities such as glass and inorganic salts are there in the sample, it increases the melting point.

02:27 Why? because since some additional amount of heat is utilized by these impurities.

02:34 Thereby the melting point is excess then of the actual value.

02:39 Got it? so, too rapid a heating of the melting point capillary means on rapid heating of the capillary, we do not observe a sharp melting point, uniform view melting is required.

02:53 And we can't measure the reading extends if it extends beyond a bulb...

Question

Please give Ace some feedback