All categories

2 years ago

HELP ASAP!!!!!!!!!!! * worth 35 points + brainliest *

Chemistry

2 answers:

gizmo_the_mogwai [7]2 years ago

7 0

Explanation:

According to Arrhenius concept:

A base is defined as a substance which donates hydroxide ions $(OH^-)$ .When they are dissolved water it gives out hydroxide ions.

$BOH(aq)\rightarrow B^+(aq)+OH^-(aq)$

For example sodium hydroxide pellets when dissolved in water gives sodium ions and hydroxide ions.

$NaOH\rightarrow Na^+(aq)+OH^-(aq)$

Properties of Arrhenius bases:

They slippery in touch
They are bitter in taste if ingested.
They turn litmus paper blue.
They react with acid to undergo neutralization reaction in which water and salt is formed.
They pH value is always greater than 7.

An acid is defined as a substance which donates hydronium ions $(H_3O^+)$ .When they are dissolved water it gives out hydronium ion.

$AH(aq)\rightarrow A^-(aq)+H_3O^+(aq)$

Musya8 [376]2 years ago

6 0

Answer:

In chemistry, a base is a substance that is slippery to the touch and has a pH greater than 7. If you were to eat a base (which you should not do) it would have bitter to the taste. A perfect example of a base is soap - when you touch soap, it feels slippery. Have you ever accidentally tasted soap? You may notice that it has a bitter taste.

These are some physical characteristics of bases, but what about the theory behind the behavior of bases when they are in a solution? There are many theories from different scientists that describe a base. One Swedish scientist, named Svante Arrhenius, came up with the theory of a base in 1884. Svante Arrhenius' definition of a base is what we now refer to as an Arrhenius base.

An Arrhenius base is a substance that, when dissolved in an aqueous solution, increases the concentration of hydroxide, or OH-, ions in the solution. An aqueous solution is a solution that has water present in it. Let's imagine dissolving a basic substance in water. According to Svante Arrhenius, when a base dissolves in an aqueous solution, it dissociates into ions and releases hydroxide ions.

NaOH dissociates into sodium, Na+, and hydroxide, OH-, ions. Because the hydroxide ions are released in the aqueous solution, the hydroxide concentration increases; therefore, NaOH is an Arrhenius base.

Sodium hydroxide, when dissolved in an aqueous solution, releases hydroxide ions in the solution.

The water above the arrow means that the NaOH is added or combined with water and dissociates into sodium, a positive cation, and one or more negative hydroxide anions.

Explanation:

Hope this helps

You might be interested in

What is sustainability

11Alexandr11 [23.1K]

Answer:

The ability to be maintained at a certain rate or level

Explanation:

3 0

3 years ago

A fossil was analyzed and determined to have a carbon-14 level that is 70 % that of living organisms. The half-life of C-14 is 5

Citrus2011 [14]

Answer: 2948

Explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{5730}=1.21\times 10^{-4}years^{-1}$

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $1.21\times 10^{-4}years^{-1}$

t = age of sample = ?

a = let initial amount of the reactant = 100

a - x = amount left after decay process = $\frac{70}{100}\times 100=70$

$t=\frac{2.303}{1.21\times 10^{-4}}\log\frac{100}{70}$

$t=2948years$

Thus the fossil is 2948 years old.

5 0

2 years ago

A 10.5 mL sample of vinegar, containing acetic acid, was titrated using 0.460 M NaOH solution. The titration required 19.13 mL o

laila [671]

Explanation:

Step 1:

A good first step for a problem like this is to write down the chemical formula and balance it.

It appears here that we have 10.5 mL of vinegar, which IS acetic acid, and 19.13 mL of 0.460 M NaOH. That will give us the following balanced chemical equation:

CH3COOH + NaOH ------> NaCH3COO + H2O

All of the constituents come out to a value of 1, conveniently.

Step 2:

Since all of our stoichiometric coefficients are one, we can use a shortcut to answer this equation. I don't know if it has a name, but I just call it the titration formula. It goes something like this:

M1 * V1 = M2 * V2

M stands for Molarity and V stands for volume. 1 and 2 being the before the reaction and after the reaction.

So, our M1 for this is going to be what the question says was used for this titration. That's 0.460M NaOH.

Our V1 is going to be the initial volume of the sample, which was 10.5 mL

Our V2 is going to be 19.13, which is the volume when we're finished.

It's clear that we don't know M2, so let's find it.

Keep in mind that it's easier to convert to liters pretty much always, so I've done that by dividing the mL values each by 1000.

Using some algebra, we can see that we now have:

0.460 M * 0.0105 L = x M * 0.01913 L

Which goes to:

$\frac{0.00483mol}{0.01913L} = 0.252 M$

<h3>So our M2, the molar concentration of acetic acid in this vinegar, is equal to 0.252 M. </h3>

3 0

3 years ago

How many moles of CH4 are in 148.6 g? Round your answer to two decimal places.

Dafna1 [17]

Answer:

9.29 mol

Explanation:

Given data:

Number of moles = ?

Mass = 148.6 g

Solution:

Number of moles = mass/ molar mass

Molar mass of CH₄ = 16 g/mol

Now we will put the values in formula.

Number of moles = 148.6 g/ 16 g/mol

Number of moles = 9.29 mol

Thus 148.6 g have 9.29 moles.

6 0

2 years ago

How many tons of zinc can be obtained from 976 tons of zinc ore that is 78.0% zinc carbonate?

kramer

First, calculating the amount of zinc carbonate by multiplying the given mass of the ore by the percent zinc carbonate.
mass of zinc carbonate = (976 tons)(0.78)
= 761.28 tons
Then, calculate for %Zn in zinc carbonate
%Zn = ((65.38) / (125.39)) x 100%
% Zn = 52.141%
tons of Zn from the sample,
mass of Zn = (761.28 tons)(0.52141)
= 396.94 tons Zn

6 0

3 years ago

Read 2 more answers