The formula for molality---> m = moles solute/ Kg of solvent
the solute here is NH₃ because it's the one with less amount. which makes water the solvent.
1) let's convert the grams of NH₃ to moles using the molar mass
molar mass of NH₃= 14.0 + (3 x 1.01)= 17.03 g/ mol
15.0 g (1 mol/ 17.03 g)= 0.881 mol NH₃
2) let's convert the grams of water into kilograms (just divide by 1000)
250.0 g= 0.2500 kg
3) let's plug in the values into the molality formula
molality= mol/ Kg---> 0.881 mol/ 0.2500 kg= 3.52 m
It's an ionic bond! Potassium is a cation, or a metal with a positive charge, and fluoride is an anion, or a nonmetal with a negative charge.
A covalent bond is the bond between two nonmetals.
Hope this helped!
Because fluorine has a higher electronegativity
Answer:
265.2amu
Explanation:
Given parameters:
Atomic mass = 254.9amu
Abundance of isotope 1 = 72%
Atomic mass of isotope 1 = 250.9amu
Abundance of isotope 2 = 100 - 72 = 28%
Unknown:
Atomic mass of isotope 2 = ?
Solution:
To find the atomic mass of isotope 2, use the expression below:
Atomic mass = (abundance of isotope 1 x atomic mass of isotope 1) + (abundance of isotope 2 x atomic mass of isotope 2)
Now insert the parameters and find the unknown;
254.9 = (0.72 x 250.9) + (0.28 x Atomic mass of isotope 2)
254.9 = 180.648 + 0.28x atomic mass of isotope 2
254.9 - 180.648 = 0.28x atomic mass of isotope 2
74.25 = 0.28 x atomic mass of isotope 2
Atomic mass of isotope 2 = 265.2amu
The equation for the reaction between the calcium nitrate and chromium sulfate to form calcium sulfate and chromium(iii) nitrate is,
3Ca(NO3)2 + Cr2(SO4)3 --> 3CaSO4 + 2Cr(NO3)3
The balanced equation shows that for every 1 mole of chromium sulfate, there will be 3 moles of calcium nitrate. Therefore for this item, there will be 4.55 moles times 3 which is equal to 13.65.
