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ehidna [41]
3 years ago
9

Help me with these two please​

Chemistry
2 answers:
Anna007 [38]3 years ago
7 0

answer -

13 is the last one

14 is the first one

explanation for number 13 - the law of conservation of mass means that the number of atoms of the products is more than the number of atoms in the reactants. the total amount of matter (atoms) before and after a chemical reaction (change), remains the same.

explanation for number 14 -  a chemical equation describes a chemical reaction. reactants are starting materials and are written on the left-hand side of the equation. products are the end result of the reaction and are written on the right-hand side of the equation.

hope this helps :) have a nice day

**please let me know if this was wrong/not what you were looking for**

prohojiy [21]3 years ago
3 0

Answer:

13.A

14.B?

on 14 i don't know

Explanation:

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Jaiden is writing a report about the structure of the atom. In her report, she says that the atom has three main parts and two s
yulyashka [42]

Answer:

The smallest constituent of an element is termed as an atom. According to Jaiden, an atom comprises two subatomic particles and three prime parts, however, this is incorrect as an atom comprises three subatomic particles and two main parts. The three subatomic particles are the protons, electrons, and neutrons. All these parts are smaller in comparison to an atom, thus, they are considered as subatomic particles.  

To be considered as an atom, an atom is needed only electrons and neutrons, like hydrogen exhibit one electron and one proton. On the other hand, the overall charge of the atom is not affected by the presence of neutrons, it is the subatomic particle that only enhances the mass of the atom.  

5 0
3 years ago
In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an ex
Kay [80]

The question is incomplete. The complete question is :

In science, we like to develop explanations that we can use to predict the outcome of events and phenomena. Try to develop an explanation that tells how much NaOH needs to be added to a beaker of HCl to cause the color to change. Your explanation can be something like: The color change will occur when [some amount] of NaOH is added because the color change occurs when [some condition]. The goal for your explanation is that it describes the outcome of this example, but can also be used to predict the outcome of other examples of this phenomenon. Here's an example explanation: The color of the solution will change when 40 ml of NaOH is added to a beaker of HCl because the color always changes when 40ml of base is added. Although this explanation works for this example, it probably won't work in examples where the flask contains a different amount of HCl, such as 30ml. Try to make an explanation that accurately predicts the outcome of other versions of this phenomenon.

Solution :

Consider the equation of the reaction between NaOH and $HCl$

  NaOH (aq) + HCl (aq) → NaCl(aq) + $H_2O (l)$

The above equation tells us that $1 \text{mole}$ of $NaOH$ reacts with $1 \text{mole}$ of $HCl$.

So at the equivalence point, the moles of NaOH added = moles of $HCl$present.

If the volume of the $HCl$ taken = $V_1$ mL and the conc. of $HCl$ = $M_1$  mole/L

The volume of NaOH added up to the color change = $V_2 \text{  and conc of NaOH = M}_2$ mole/L

Moles of $HCl$ taken = $V_1 \ mL \times M_1 \ mol/100 \ mL = V_2M_2 \times 10^{-3}$  moles.

The color change will occur when the moles of NaOH added is equal to the moles of $HCl$ taken.

Thus when $V_1 M_1 \times 10^{-3} = V_2M_2 \times 10^{-3}$

or   when    $V_1M_1 = V_2M_2$

or $V_2=\frac{V_1M_1}{M_2}$  mL of NaOH added, we observe the color change.

Where $V_1, M_1$ are the volume and molarity of the $HCl$ taken.

$M_2$ is the molarity of NaOH added.

When both the NaOH and $HCl$ are of the same concentrations, i.e. if $M_1=M_2$, then $V_2=V_1$

Or the 40 mL of $HCl$ will need 40 mL of NaOH for a color change and

30 mL of $HCl$ would need 30 mL of NaOH for the color change (provided the concentration $M_1=M_2$)

7 0
2 years ago
1. The pressure and temperature of a gas are held constant. Which of the following is true for the volume of the gas?
katovenus [111]
<h3>1.</h3>

C) The volume of the gas is proportional to the number of moles of gas particles.

The Avogadro's law applies to ideal gases with constant pressure and temperature. By that law, the volume of an ideal gas is proportional to the number of moles of particles in that gas.

<h3>2.</h3>

B) The gas now occupies less volume, and the piston will move downward.

Boyle's Law applies to ideal gases with a constant temperature. The volume of an ideal gas is inversely related to its pressure. A high pressure drives gas particles together, such that they occupy less volume. The gas trapped inside the piston has a smaller volume. As a result, the the piston will move downward.

Alternatively, consider the forces acting on the piston. Both the atmosphere and gravity are dragging the piston down. In order for it to stay in place, the gas below it must exert a pressure to balance the two forces. Now the pressure from outside has increased. The gas inside needs to increase its pressure. It needs a smaller volume to create that extra pressure. As a result, its volume will decrease, and the piston will move downwards.

6 0
3 years ago
Read 2 more answers
A pharmaceutical company wants to test the efficiency of its new drug production techniques so they run 3 shifts of production f
spayn [35]

The percentage yield of the  new production technique is 82.8%

<h3>What is the percentage yield?</h3>

Production is the procedure by which finished products are obtained form the raw materials. The production process involves the passing of raw materials through a certain procedure that involves the use of certain machines and equipment to give us the required products.

We are told in the question that there are three shifts;

Shift 1 produces 4562 grams

Shift 2 produces 5783 grams

Shift 3 produces 5247 grams

Average production from the three shifts = 4562 grams + 5783 grams +  5247 grams/3 = 5197 grams

The theoretical average yield is =  7000 grams + 7000 grams + 7000 grams/3 = 7000 grams

Now the percentage yield = actual yield/ theoretical yield * 100/1

percentage yield = 5197 grams/7000 grams * 100/1

percentage yield = 82.8%

Learn more about percentage yield :brainly.com/question/27492865

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3 0
2 years ago
23.5 L of h2 is stored at a pressure of 58.7 Kpa what volume would the gas take up at stp
stepan [7]

Answer:-  13.6 L

Solution:- Volume of hydrogen gas at 58.7 Kpa is given as 23.5 L. It asks to calculate the volume of hydrogen gas at STP that is standard temperature and pressure. Since the problem does not talk about the original temperature so we would assume the constant temperature. So, it is Boyle's law.

Standard pressure is 1 atm that is 101.325 Kpa.

Boyle's law equation is:

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From given information:-

P_1 = 58.7 Kpa

V_1 = 23.5 L

P_2 = 101.325 Kpa

V_2 = ?

Let's plug in the values and solve it for final volume.

58.7Kpa*23.5L=101.325Kpa*V_2

On rearranging the equation for V_2

V_2=\frac{58.7Kpa*23.5L}{101.325Kpa}

V_2 = 13.6 L

So, the volume of hydrogen gas at STP for the given information is 13.6 L.

3 0
3 years ago
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