Answer:
547.5g
Explanation:
To get the mass, you need moles.
moles = (molarity)(Liters)
moles = (1.230M)(4.200L) = 5.166 moles Na2CO3
Now, just use stoichiometry
molar mass of Na2CO3 = 2(mass of Na) + (mass of C) + 3(mass of O)
= 2(22.9) + 12.01 + 3(16) = 105.99g/mol
5.166moles(105.99g/mol)
= 547.544
But, the measurements given had 4 significant figures, so in chemistry we write:
547.5g
Answer:
B. only particle Z
Explanation:
In the case of subatomic particles, those positive and neutral are located in the nucleus, and those with a negative charge on the outside.
Answer:
a. equal to
Explanation:
The <em>osmotic pressure</em> is calculated by the formula:
π = <em>i</em> * M * R * T
Where π is the osmotic pressure, M is the concentration, R is a constant, T is temperature and <em>i</em> is the van't Hoff's factor (the number of ions a compound forms when dissolved in water,<u> for both NaCl and KBr is 2</u>).
Because R is always the same, and <u>Temperature and Concentration are equal between the two solutions</u>, the osmotic pressure of both solutions are also equal.
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
