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4 years ago

PLEASE HELP WITH ALL

Chemistry

2 answers:

Tpy6a [65]4 years ago

7 0

Answer:

Question 1: Correct 3 and 4

Question 2: All can be corrected except item 2.

Question 3: Correct 1

Question 4: Correct 1

Question 5: Correct 1

Explanation:

Question 1: The law of conservation of mass explains that “In an isolated system, during any ordinary chemical reaction, the total mass in the system remains constant, that is, the mass consumed of the reagents is equal to the mass of the products obtained”, therefore, statements 3 are correct, which tells us that we must begin and end with the same amount of matter, and 4, since we cannot create or destroy matter.

Question 2: When a chemical reaction occurs, according to the initial compounds (reagents), it can be seen in various ways how a change in the system occurs, which indicates that a chemical reaction occurred, many of them can be identify with our senses (change of color, change of temperature, change of state of aggregation of the reagents, etc.), it is clear that they do not have problems that have all these statements together, with which of these happen, we could affirm that it had a chemical reaction.

On the other hand, changes that can be easily undone (affirmation 2) are more related to physical phenomena, in which the intimate composition of matter (such as a change of state) does not vary, a difference in chemical reactions .

Question 3: When a chemical reaction occurs, the substances that are initially found (reagents) change the intimate structure of matter, breaking and / or forming bonds of the compounds to form new bonds, and thus, new substances (products). That is why the correct statement is 1, in the case of the other statements, physical phenomena are being described, in which there are no breaking of bonds in the initial compounds to form new substances, simply, state changes occur in matter, but no new compounds are formed.

Question 4: In changes of state, there are no changes in the intimate structure of matter, so they are physical phenomena. The only thing that varies in the changes of state of matter, is the kinetic energy with which the particles of the system move, due to the variation in temperature.

Question 5: Unlike physical reactions, in chemical reactions there are bond ruptures and / or rearrangement of atoms of the initial compounds (reagents) to form new bonds and structures, and thus, new compounds (reaction products). In addition, these reactions comply with the law of conservation of mass, so that matter cannot be created or destroyed, as well as energy.

Gala2k [10]4 years ago

5 0

Answer:

Question 1: D

Question 2: B C E F

Question 3: A

Question 4: A

Question 5: A

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What is the molarity of the Ca(OH)2 solution if 32.00 mL of Ca(OH)2 requires 16.08 mL of a 2.303 M solution for complete titrati

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For this problem we just need to remember the equation and that the volume is always in liters: MaVa=MbVb

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This is a two step process: stoichiometry and using the answer from the first part to plug and chug it into the Molariy equation.

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So next, we can set it to the mass of the acid using this equation: Molar Mass= mass/ moles

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Explanation:

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2 years ago

Malonic acid, h2c3h2o4, is a diprotic acid with ka1= 1.5 x 10-3and ka2= 2.0 x 10-6. what is the concentration of the malonate an

Bess [88]

In a 0.15 m solution of malonic acid, the amount of the malonate anion, c3h2o42-, is $1.68*10^{-4} M$ .

Explanation:

For the first equlibria;

initial concentration of $H_{2}C_{3}H_{2}OH=0.15$

initial concentration of $HC_{3}H_{2}O_{4}^{-} =0$

initial concentration of $H^{+} =0$

Let concentration change of $H_{2}C_{3}H_{2}OH=-x$

Let concentration change of $HC_{3}H_{2}O_{4}^{-} =+x$

Let concentration change of $H^{+} =+x$

Let concentration in equilibrium state of $H_{2}C_{3}H_{2}OH=0.15-x$

Let concentration in equilibrium state of $HC_{3}H_{2}O_{4}^{-} =x$

Let concentration in equilibrium state of $H^{+} =x$

Therefore, $Ka_{1}=\frac{x*x}{0.15-x}=\frac{1.5*10^{-3}}{1} =\frac{x^{2}}{0.15-x}$

$x^{2}+0.0015x-0.000225=0$

Which is a quadratic equation in x, solving it gives;

$x=0.01427$

Therefore, $HC_{3}H_{2}O_{4}^{-} =x= 0.01427M$

Now for the second equlibria;

initial concentration of $HC_{3}H_{2}O_{4}^{-}=0.01427$

initial concentration of $C_{3}H_{2}O_{4}^{2-} =0$

initial concentration of $H^{+} =0$

Let concentration change of $HC_{3}H_{2}O_{4}^{-}=-x$

Let concentration change of $C_{3}H_{2}O_{4}^{2-} =+x$

Let concentration change of $H^{+} =+x$

Let concentration in equilibrium state of $HC_{3}H_{2}O_{4}^{-}=0.01427-x$

Let concentration in equilibrium state of $C_{3}H_{2}O_{4}^{2-} =x$

Let concentration in equilibrium state of $H^{+} =x$

Therefore, $Ka_{2}=\frac{x*x}{0.01427-x}=\frac{2.0*10^{-6}}{1} =\frac{x^{2}}{0.01427-x}$

$2.854*10^{-8}-(2.0*10^{-6})x=x^{2}$

Therefore, $C_{3}H_{2}O_{4}^{2-} =x= 1.68*10^{-4}M$

<h3>What is a malonic acid?</h3>

The chemical formula of malonic acid is CH2(COOH)2. Malonates include the ionized form of malonic acid as well as its esters and salts. For instance, the diethyl ester of malonic acid is called diethyl malonate.

Polyester and polymers both employ malonic acid as a precursor. Both the scent business and the flavoring sector utilize it. It is employed to regulate acidity. Malonic acid contributes to the production of fatty acids in people. Malonic acid has been found in a number of foods outside of the human body, including red beets, corn, scarlet beans, common beets, and cow milks, although its presence has not been defined. The group of organic substances known as dicarboxylic acids and derivatives includes malonic acid, also known as malonate or H2MALO.

To know more about malonic acid, visit:

brainly.com/question/13943912?referrer=searchResults

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1 year ago