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3 years ago

What is the arrhenius definition of a base?

2 answers:

4 0

The Arrhenius definition of acid-base reactions, which was devised by Svante Arrhenius, is a development of the hydrogen theory of acids. ... An Arrhenius base is a substance that dissociates in water to form hydroxide (OH -) ions. In other words, a base increases the concentration of OH - ions in an aqueous solution.

vaieri [72.5K]3 years ago

3 0

A substance that increases H3O+ concentration when it is dissolved in water.

A substance that increases OH– concentration when it is dissolved in water.

A compound that donates protons.

A compound that accepts protons.

it is the last option

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Why are hydrogen, lithium, and sodium classified as reactive elements?

Sergeu [11.5K]

The alkali metals and hydrogen are reactive because they have only one electron to give in order to complete their valence shell. It is easier to give that one electron so when given the opportunity they will. This means they will react with anything polar or willing to take an electron.

4 0

4 years ago

Which statements best describe half-lives of radioactive isotopes? Check all that apply.

Igoryamba

Answer:

The half-life varies depending on the isotope.

Half-lives range from fractions of a second to billions of years.

The half-life of a particular isotope is constant.

3 0

3 years ago

Read 2 more answers

A) The average molecular speed in a sample of Ar gas at a certain temperature is 391 m/s. The average molecular speed in a sampl

diamong [38]

Answer:

For A: The average molecular speed of Ne gas is 553 m/s at the same temperature.

For B: The rate of effusion of $SO_2$ gas is $1.006\times 10^{-3}mol/hr$

Explanation:

For A:

The average molecular speed of the gas is calculated by using the formula:

$V_{gas}=\sqrt{\frac{8RT}{\pi M}}$

$V_{gas}\propto \sqrt{\frac{1}{M}}$

where, M is the molar mass of gas

Forming an equation for the two gases:

$\frac{V_{Ar}}{V_{Ne}}=\sqrt{\frac{M_{Ne}}{M_{Ar}}}$ .....(1)

Given values:

$V_{Ar}=391m/s\\M_{Ar}=40g/mol\\M_{Ne}=20g/mol$

Plugging values in equation 1:

$\frac{391m/s}{V_{Ne}}=\sqrt{\frac{20}{40}}\\\\V_{Ne}=391\times \sqrt{2}=553m/s$

Hence, the average molecular speed of Ne gas is 553 m/s at the same temperature.

For B:

Graham's law states that the rate of diffusion of a gas is inversely proportional to the square root of the molar mass of the gas. The equation for this follows:

$Rate\propto \frac{1}{\sqrt{M}}$

Where, M is the molar mass of the gas

Forming an equation for the two gases:

$\frac{Rate_{SO_2}}{Rate_{Xe}}=\sqrt{\frac{M_{Xe}}{M_{SO_2}}}$ .....(2)

Given values:

$Rate_{Xe}=7.03\times 10^{-4}mol/hr\\M_{Xe}=131g/mol\\M_{SO_2}=64g/mol$

Plugging values in equation 2:

$\frac{Rate_{SO_2}}{7.03\times 10^{-4}}=\sqrt{\frac{131}{64}}\\\\Rate_{SO_2}=7.03\times 10^{-4}\times \sqrt{\frac{131}{64}}\\\\Rate_{SO_2}=1.006\times 10^{-3}mol/hr$

Hence, the rate of effusion of $SO_2$ gas is $1.006\times 10^{-3}mol/hr$

8 0

3 years ago

During an exothermic chemical reaction, a solid is consumed and a gas produced. a. Yes b. No c. Can't decide with information gi

kiruha [24]

Answer: The given statement is true.

Explanation:

For the reaction to be spontaneous, the Gibbs free energy of the reaction must come out to be negative.

The equation used to calculate Gibbs free energy follows:

$\Delta G=\Delta H-T\Delta S$

Exothermic reactions are defined as the reactions in which energy is released in the form of heat. The enthalpy change $(\Delta H)$ of the reaction comes out to be negative for this kind of reaction.

Entropy change is defined as the change in the measure of randomness in the reaction. It is represented as $(\Delta S)$ . Randomness of gaseous particles is more than that of liquid which is further more than that of solids.

We are given:

A solid substance is converting into a gaseous substance.

$\text{Solid}\rightarrow \text{Gas}$

As, the entropy is increasing. So, the entropy change is positive.

Thus, the above reaction is spontaneous. $\Delta G=-ve-(+ve)\\\\\Delta G=-ve$

Hence, the given statement is true.

4 0

4 years ago

Which of the term best describe the developing country? Select the three

Romashka-Z-Leto [24]

A developing country (or a low and middle income country (LMIC), less developed country, less economically developed country (LEDC), or underdeveloped country) is a country with a less developed industrial base and a low Human Development Index (HDI) relative to other countries.

8 0

4 years ago

Read 2 more answers