Platinum has a molar mass of 195 g/mol. if you have a ring that contains 2.3 g of platinum, how many moles does it contain? (a)0.012 mol (b) 85 mol (c)450 mol (d) 7.2 x 10^21 mol

correct answer is option (A) 0.012 mol

Explanation:

Given:

Molar mass of the platinum, M = 195 g/mol

Mass of the platinum in the ring, m = 2.3 g

Now,

the number of moles (n) is calculated as :

thus,

on substituting the respective values in the formula, we get

or

n = 0.01179 mol ≈ 0.012 mol

Hence, the correct answer is option (A) 0.012 mol

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

yup its correct its: c) b b