In an aqueous solution, which substance yields hydrogen ions as the only positive ion? (1) $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$, (2) $\mathrm{CH}_{3} \mathrm{COOH}$, (3) KH, (4) KOH.

If 1 mol of each of the following substances were dissolved in 1 L of water, which solution would contain the highest concentration of $\mathrm{H}_{3} \mathrm{O}^{+}$ ions? (1) $\mathrm{CH}_{3} \mathrm{COOH}$, (2) NaCl, (3) KBr, (4) $\mathrm{Ba}(\mathrm{OH})_{2}$.

Which species is classified as an Arrhenius base? (1) $\mathrm{CH}_{3} \mathrm{OH}$, (2) LiOH, (3) $\mathrm{PO}_{4}^{3-}$, (4) $\mathrm{CO}_{3}^{2-}$

Give the formula of a negative ion that would have the same number of electrons as each of the following positive ions. a. $\mathrm{K}^{+}$ b. $\mathrm{Mg}^{2+}$ c. $\mathrm{Sr}^{2+}$ d. $\mathrm{Cs}^{+}$

(a) An oxygen-16 ion with a mass of $2.66 \times 10 ^ { - 26 } \mathrm { kg }$ travels at $5.0 \times 10 ^ { 6 } \mathrm { m } / \mathrm { s }$ perpendicular to a 1.20-T magnetic field, which makes it move in a circular arc with a 0.231-m radius. What positive charge is on the ion? (b) What is the ratio of this charge to the charge of an electron? (c) Discuss why the ratio found in (b) should be an integer.

Use inversion to turn the following statement into question.

Il fait mauvais aujourd’hui.

At $50 ^ { \circ } \mathrm { C }$ the ion-product constant for $H_2O$ has the value $K _ { w } = 5.48 \times 10 ^ { - 14 }$ Based on the change in $K_w$ with temperature, predict whether $\Delta H$ is positive, negative, or zero for the autoionization reaction of water: $2 \mathrm { H } _ { 2 } \mathrm { O } ( l ) \rightleftharpoons \mathrm { H } _ { 3 } \mathrm { O } ^ { + } ( a q ) + \mathrm { OH } ^ { - } ( a q )$

$(a)$ An oxygen-$16$ ion with a mass of $2.66 \times 10^{-26} \mathrm{~kg}$ travels at $5.0 \times 10^6 \mathrm{~m} / \mathrm{s}$ perpendicular to a $1.20 \mathrm{~T}$ magnetic field, which makes it move in a circular arc with a $0.231 \mathrm{~m}$ radius. What positive charge is on the ion? $(b)$ What is the ratio of this charge to the charge of an electron? $(c)$ Discuss why the ratio found in $(b)$ should be an integer.

Menelao Clothing Co. designs and manufactures fashionable dothing for children in a variety of designs, colours and sizes. Explain two benefits of this production method to Menelao Clothing Co.

Potassium hydroxide is classified as an Arrhenius base because KOH contains: (1) $\mathrm{OH}^{-}$ ions. (2) $O^{2-}$ ions. (3) $\mathbf{K}^{+}$ ions. (4) $H^{+}$ ions.

According to the Arrhenius theory, when a base is dissolved in water it will produce a solution containing only one kind of negative ion. To which ion does the theory refer? (1) hydride, (2) hydroxide, (3) hydrogen, (4) hydronium.

Potassium ions $\left(\mathrm{K}^{+}\right)$have a positive charge. What happens to a potassium atom's electrons when it becomes an ion?

Write the complete chemical formula (symbol and charge) for the positive ion present in each of the following ionic compounds.

a. KCl

b. CaS

c. $\text{MgF}_2$

d. $\text{Al}_2\text{S}_3$

A solution of a base differs from a solution of an acid in that the solution of a base: (1) is able to conduct electricity, (2) is able to cause an indicator color change, (3) has a greater $\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]$, (4) has a greater $\left[O H^{-}\right]$.