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
A bond between two atoms that SHARE electrons
Answer:
Rb<K<Ga<As<Se<S
Explanation:
We must remember that first ionization energy decreases down the group and increases across the period.
First ionization energy decreases down the group because of the addition of more shells which increases the distance between the nucleus and the outermost electron. Hence, Rb has a lower ionization energy that K.
Across the period, increase in the size of the nuclear charge causes the pull of the nucleus on the outermost electrons to increase thereby increasing the ionization energy. Hence ionization energy increases across the period. For this reason, the ionization energy of Ga<As<Se as shown.
Answer:
H2SO4
Explanation:
An electrolyte is a chemical compound that conducts electricity by changing into ions when melted or dissolved into a solution. An example of an electrolyte is sodium chloride.
Strong acids such as sulfuric acid (H2SO4), and strong bases such as potassium hydroxide (KOH), and sodium hydroxide (NaOH) are frequently used as electrolytes due to their strong conducting abilities.
