That is not a question/problem and makes no sense whatsoever
Salutations!
What causes a substance to change states of matter?
Energy causes a substance to change states of matter. A matter needs energy to melt, evaporate, boil. Remember: Energy has a sudden change, but the temperature remains absolutely the same. An example of a change in energy is when ice is melting.
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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
Answer:
The net ionic equation is
C6H5COOH+ CN-= C6H5COO- + HCN
Explanation:
From the ionic equation
C6H5COOH + Na+ + CN- = C6H5COO- + Na+ + HCN
Only sodium is the spectator ion, so it cancels out, since C6H5COOH and HCN do not ionize completely they are left undissociated