Answer:
1.23 M
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = given mass of NaCl = 7.2 g
As we know , the molecular mass of NaCl = 58.5 g/mol
Moles is calculated as -
n = w / m = 7.2 g / 58.5 g/mol = 0.123 mol
Molarity is calculated as -
V = 100ml = 0.1 L (since , 1 ml = 1/1000L )
M = n / V = 0.123 mol / 0.1 L = 1.23 M
Helium is very difficult to liquify because it only exists in its liquid form at an extremely low temperature. This temperature is <span>low temperature of −269 °C (about 4 K or −452.2 °F). It is only possible to maintain liquid helium in a highly artificial environment where this low temperature can be created. </span>
I say it’s 9 moles , hope this is right
If u click on all of them it gives u an A+ and doesn’t even read what u wrote. So u never really have to try hard on the writing parts just tell them u included them all
