What is the mass in grams of NaCN in 120.0mL of a 2.40x10-5 M
solution?

ANSWER: 1.41 x grams

EXPLANATION:

1. The formula for mass is m=nM therefore we need to find moles (n) because we don't have that yet.

n = ( × ) x 0.12     (I converted 120.0 mL to L, which makes it 0.12)

n = 0.00000288 mol

2. Now we can find the mass.

m = n x M

m = 0.00000288 x 49.0072   (molar mass, M, of NaCN is 49.0072)

m = 0.00014114073 grams ≈ 1.41 x grams

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

→

i think its 100.

hope this !