How many moles of mgcl2 are there in 338 g of the compound

atomic mass of magnesium = 24.305

atomic mass of chlorine = 35.453

molecular mass of MgCl2 = 24.305+2*35.453 = 95.211

Number of moles in 338 g of pure MgCl2

= 338/95.211 = 3.55001 moles

Ans. there are 3.55 moles of MgCl2 in 338 g of the substance.

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.