Help me please please please please .

Question 1: Which mixtures can be separated by magnet?

Answers: The safety pins and sand mixture; The thumb tacks and sand mix.

Reason: The magnet pulls on the metal to help pull it apart from the nonmetal item such a sand or sugar.

Question 2: Which mix cannot be separated by magnet?

Answers: Sand and sugar mix; safety pins and thumb tacks mix

Reason: For the sand and sugar mix, there isn't any metal to pull on. These particles will stay where they are. In contrast, the safety pins and thumb tacks are both metal (or have both have metal parts) so they will be pulled on equally. There isn't a difference like in problem 1 which allows for the separation to happen. We need a metal vs nonmetal mix so that we can pull out the metal with the magnet. More specifically, the metal must be magnetic or be able to be affected by a magnet. We consider this type of material ferromagnetic. Unfortunately some metals aren't able to be magnetized, but I'm assuming that your teacher is referring to magnetic metals for the safety pins and thumb tacks.

Question 3: How do you classify materials not attracted to a magnet?

We consider them to be non-ferromagnetic materials

The term "ferro" refers to "iron" which is a very magnetic material. The ancients knew that iron had this property as this material is fairly easily discovered in the earth. Some metals don't have this magnetic property and a magnet will not affect it.

Question 4: How do you classify materials attracted to a magnet?

Any ferromagnetic material (eg: iron or steel)

Reason: Refer to problem 3

Question 5: How are the mixtures separated?

The magnet pulls on the ferromagnetic material to separate it from the nonferromagnetic material.

Refer back to the previous questions for more info.

answer : (a) volume of the gas = 8.67 ×   l

                (b) second virial coefficient b = -1.21226 l/mole

solution :   given,     t = 300k

                                p = 20atm

                                z = 0.86

                                n = 8.2 mmoles = 8.2 × moles

                                r =   0.082 l atm/k/mol

        find,     (a) volume of gas   and (b) second virial coefficient b at 300k.

formula used :            

                          and            

(a)            

                    = \times 0.082\times 300}{20}[/tex]

                    = 8.67 ×   l

(b)      

                    = (0.00867-1) × 8.659

                    = - 8.5839 l/mole