Which ph is more acidic, a ph of 3, a ph of 7, or a ph of 9?.

Which produces the most energy? A. passing 5 kg of water through a hydroelectric power plant. B. fissioning 5 kg of uranium. C.

blagie [28]

Answer:

D. fusing 5 kg of hydrogen.

Explanation:

8 0

3 years ago

Calculate the electric double layer thickness of a alumina colloid in a dilute (0.1 mol/dm3) CsCI electrolyte solution at 30 °C.

Ad libitum [116K]

Explanation:

The given data is as follows.

Concentration = 0.1 $mol/dm^{3}$

= 0.1 \frac{mol dm^{3}}{dm^{3}} \frac{10^{3}}{dm^{3}} \times \frac{6.022 \times 10^{23}}{1 mol} ions

= $6.022 \times 10^{25} ions/m^{3}$

T = $30^{o}C$ = (30 + 273) K = 303 K

Formula for electric double layer thickness ( $\lambda_{D}$ ) is as follows.

$\lambda_{D}$ = $\frac{1}{k} = \sqrt \frac{\varepsilon \varepsilon_{o} K_{g}T}{2 n^{o} z^{2} \varepsilon^{2}}$

where, $n^{o}$ = concentration = $6.022 \times 10^{25} ions/m^{3}$

Hence, putting the given values into the above equation as follows.

$\lambda_{D}$ = $\sqrt \frac{\varepsilon \varepsilon_{o} K_{g}T}{2 n^{o} z^{2} \varepsilon^{2}}$

= $\sqrt \frac{78 \times 8.854 \times 10^{-12} c^{2}/Jm \times 1.38 \times 10^{-23}J/K \times 303 K}{2 \times 6.022 \times 10^{25} ions/m^{3} \times (1)^{2} \times (1.6 \times 10^{-19}C)^{2}}$

= $9.669 \times 10^{-10}$ m

or, = $9.7 A^{o}$

= 1 nm (approx)

Also, it is known that $\lambda_{D}$ = $\sqrt \frac{1}{n^{o}}$

Hence, we can conclude that addition of 0.1 $mol/dm^{3}$ of KCl in 0.1 $mol/dm^{3}$ of NaBr " $\lambda_{D}$ " will decrease but not significantly.

7 0

3 years ago

A solid calcium metal reacts with molecular oxygen. WORD EQUATION = CHEMICAL EQUATION =

Ne4ueva [31]

Word equation - calcium + oxygen -> calcium oxide
Chemical equation - Ca + O2 -> CaO2

Hope this helps!

5 0

3 years ago

The lattice energy of a salt is related to the energy required to separate the ions. For which of the following pairs of ions is

Kay [80]

Answer: The Lattice energy is the energy required to separate an ionic solid into its component gaseous ions or

It is the energy released when gaseous ions combine to form an ionic solid.

Explanation:

The lattice energy depends on the ionization energies and electron affinities of atoms involved in the formation of the compound. The ionization energies and electron affinities also depends on the ionic radius and charges of the ions involved. As the ionic radius for cations increases down the groups, ionization energy decreases, whereas, as ionic radii decreases across the periods , ionization energy increases. The trend observed for anions is that as ionic radii increase down the groups, electron affinity decreases. Across the period, as ionic radii increases electron affinity increases. Also, as the charge on the ion increases, it leads to an increase in energy requirement/content.

Therefore, for compounds formed from cations and anions in the same period, the highest charged cation and anion will have the highest lattice energy. For example, among the following compounds: Al2O3 (aluminium oxide), AlCl3 (aluminium chloride), MgO, MgCl2 (magnesium chloride), NaCl, Na2O (sodium oxide); Al2O3(aluminium oxide) will have the highest lattice energy, thus will be hardest to break apart because its ions have the highest charge.

5 0

2 years ago

How many Groups is the modern periodic table divided into? A. 2 B. 3 C. 7 D. 18

RSB [31]

18

In chemistry, a group is a column of elements in the periodic table of the chemical elements. There are 18 numbered groups in the periodic table; the f-block columns are not numbered.

4 0

2 years ago

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