valence of magnesium is 2
and valence of sulfate-ion is 2 too
answer: MgSO4•7H2O
Given:
257J of heat
5500g of mercury
increase by 5.5
degrees Celsius
Required:
Specific heat of
mercury
Solution:
H
= mCpT
257J = (5500g of
mercury) Cp (5.5 degrees Celsius)
Cp = 8.5 x 10^-3
Joules per gram per degree Celsius
I'm gonna go ahead and guess, and say its B.
decameters - meters: multiply by 10
meters to meters: multiply by 1
centimeters to meters: divide by 100
millimeters to meters: divide by 1000
For the rows at the bottom:
hectometer row: 100, multiply by 100, 4500
decameter row: 10, multiply by 10, 450
meter row: 1, multiply by 1, 45
decimeter row: 0.1, divide by 10, 4.5
centimeter row: 0.01, divide by 100, 0.45
im guessing theres a millimeter row at the bottom:
millimeter row: 0.001, divide by 1000, 0.045
hope this helps!
Answer:
27.60 g urea
Explanation:
The <em>freezing-point depression</em> is expressed by the formula:
In this case,
- ΔT = 5.6 - (-0.9) = 6.5 °C
m is the molality of the urea solution in X (mol urea/kg of X)
First we<u> calculate the molality</u>:
- 6.5 °C = 7.78 °C kg·mol⁻¹ * m
Now we<u> calculate the moles of ure</u>a that were dissolved:
550 g X ⇒ 550 / 1000 = 0.550 kg X
- 0.84 m = mol Urea / 0.550 kg X
Finally we <u>calculate the mass of urea</u>, using its molecular weight:
- 0.46 mol * 60.06 g/mol = 27.60 g urea