This mystery element has a reputation for being tough. That's because when combined with other elements, it forms strong,

durable compounds. Some are nearly as hard as diamonds-the

hardest material on Earth. But in its pure form, the grayish-

white transition metal is soft enough to cut with a saw. Most

of the mystery element- about 75 percent-comes from

China. There are also large deposits in Canada, Russia, and the

U. S.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

answerleaving cheese out to get moldy;