Answer:
The minimum mass of ethylene glycol = 6.641 Kg
Explanation:
Where T_f = freezing point of pure solvent water, 0°C
T_f'= Freezing point of solvent after mixture
K_f = Freezing point depression constant = 1.86 °C/m
Moecular weight of ethylene glycol = 60 g/mol
Weight of ethylene glycol = 14.5 Kg= 14.5×10^3 g
molality of ethylene glycol
Substitute the values to calculate m
by formula
calculating we get w = 6641.93 g
Therefore, The minimum mass of ethylene glycol = 6.641 Kg
4Al + 3O2 —> 2AL2O3
Answer is D
Answer:
8.9x10¹⁷ atoms of Al are present
Explanation:
To find the number of atoms from the mass of an atom we must convert, as first, the mass to moles using the molar mass of the atom (26.98g/mol For Aluminium).
Then, we must convert the moles to atoms knowing that 1mol = 6.022x10²³ atoms.
<em>Moles Aluminium:</em>
4.0x10⁻⁵g * (1mol / 26.98g) = 1.483x10⁻⁶ moles Al
<em>atoms:</em>
1.483x10⁻⁶ moles Al * (6.022x10²³ atoms / mol) =
<h3>8.9x10¹⁷ atoms of Al are present</h3>
Answer:
B Fluorine is the most reactive because it has 7 electrons in the outer shell.
Explanation:
The valid conclusion about the reactivity of the elements is that fluorine is the most reactive because it has 7 electrons in the outer shell.
- Reactivity of elements is in a bid to attain a stable configuration of their atoms.
- Fluorine belongs to group 7 on the periodic table.
- To complete its octet, it requires just one electron.
- This makes it very reactive
- On getting an electron, it becomes like the nearest noble gas, Neon.