Leslie is a forensic scientist who is using the precipitin test at a crime scene. What
question is Leslie MOST likely trying to answer?

It requires 60 mL of 0.20 M sodium hydroxide [tex](NaOH)[/tex] to neutralize 25 mL of carbonic acid [tex](H_2CO_3)[/tex], hence the carbonate ions concentration is [tex]0.24M[/tex].

Given:

Reaction:

[tex]\to \bold{2NaOH + H_2CO_3 \to Na_2CO_3 + 2H_20 }[/tex]

[tex]NaOH[/tex] volume [tex](V_B) = 60 \ ml[/tex]  

[tex]H_2CO_3[/tex] Volume [tex](V_A) = 25\ ml[/tex]  

[tex]NaOH[/tex] Molarity [tex](C_B) = 0.20\ M[/tex]

[tex]H_2CO_3[/tex] moles [tex](n_A) = 1[/tex]

[tex]NaOH[/tex] moles [tex](n_B) = 2[/tex]

To find:

[tex]H_2CO_3[/tex] Molarity [tex](C_A) =?[/tex]

Solution:

Using the neutralization reaction:  

[tex]\to \frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B} \\\\[/tex]

[tex]\to C_B = 0.2\ M \\\\ \to n_A = 1 \\\\ \to n_B = 2 \\\\ \to V_B = 60\ ml \\\\ \to V_A = 25\ ml[/tex]

Calculating the [tex]C_A[/tex]:

 [tex]\to \frac{C_A \times 25}{0.2 \times 60} =\frac{1}{2} \\\\\to C_A =\frac{1 \times 0.2 \times 60}{2 \times 25} \\\\\to C_A =\frac{1 \times 2 \times 12}{2 \times 5 \times 10} \\\\ \to C_A =\frac{ 12}{ 5 \times 10} \\\\\to C_A = \frac{6}{5 \times 5} \\\\\to C_A = \frac{6}{25} \\\\\to C_A=0.24\ M[/tex]

Therefore, the concentration of carbonic acid is "0.24M".

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The concentration of carbonic acid( H₂CO₃) is 0.24 M.

The given reaction:

2 NaOH + H₂CO₃ → Na₂CO₃ + 2H₂O

Volume of NaOH  = 60mL

Volume of H₂CO₃ = 25 mL

Molarity of NaOH= 0.20M

To find:

Molarity of H₂CO₃=?

2 moles of NaOH and 1 mol of H₂CO₃ reacts to give 1 mol of Na₂CO₃.

Using the neutralization reaction:  

Consider A to be NaOH and B to be  H₂CO₃

[tex]\frac{\text{Number of moles of A}}{\text{Number of moles of B}} =\frac{\text{Molarity of A*Volume of A}}{\text{Molarity of B*Volume of B}}[/tex]

On substituting the values in order to calculate molarity of H₂CO₃:

[tex]\text{Molarity of B}=\frac{1*0.2*60}{2*25} \\\\\text{Molarity of B}=0.24M[/tex]

Therefore, the concentration of H₂CO₃ is 0.24 M.

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Answer:

B a shared pair of electrons (2)

Explanation:

In Lewis structures, a single line represents a single pair of electrons. This means that the elements share 2 electrons or one pair of electrons

Hope this helps!

The shared electrons behave as if they belong to both atoms in the bond and bind the two atoms together to form a molecule. The shared electrons are typically depicted as a line (—) connecting the bonded atoms. (A line in a Lewis structure represents two electrons. Therefore, option A is correct.

Lewis structures, also known as Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures, are diagrams that depict the bonding between atoms in a molecule as well as any lone pairs of electrons that may exist.

A Lewis structure is based on the octet rule, which states that atoms share electrons in order for each atom to have eight electrons in its outer shell. An oxygen atom, for example, has six electrons in its outer shell.

Gilbert N. Lewis, who introduced the Lewis structure in his 1916 article The Atom and the Molecule, was named after it. Lewis structures expand on the electron dot diagram concept by adding lines between atoms to represent shared pairs.

Thus, option A is correct.

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Answer:

nitrogen have more protons per atom than phosphorus

Oxygen and fluorine are the two elements that have more protons per atom than the element phosphorus.

Phosphorus (P), a nonmetallic chemical element of something like the nitrogen group (Group 15 [Va] of the periodic table), is a colorless, semitransparent, soft, sticky solid that glows in the dark at room temperature.

Hennig Brand, a German businessman with an interest in alchemy, appears to have discovered phosphorus around 1669. Brand left 50 buckets of pee alone till they putrified and "produced worms." He then reduced the urine to a paste and burned it with sand to extract elemental phosphorus first from combination.  Oxygen and fluorine are the two elements that have more protons per atom than phosphorus.

Therefore, oxygen and fluorine are the two elements that have more protons per atom than phosphorus.

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Answer:

20g

Explanation:

hope helpful.............

Answer:

cellular respiration

Explanation:

hope this helps :)

brainliest plzzzzzzz

Answer: They are located along the upper right side of the periodic table.

Explanation: Malleability is a physical property that some elements of matter have that can be broken down into sheets to give them a certain shape without breaking. This physical property belongs to plasticity. It is a characteristic that some metals have, sheets of said metal can be obtained. The heat needs to be increased, some examples are gold, platinum, zinc, tin, etc.

Answer:

i belive the answer you are looking for is A.. hope this helps!

Explanation:

im not really 100% certain of this answer due to the fact i am a little rusty.

The statement is true in this situation is C. The size of Ffric is the same as the size of Fapp:

From the diagram, since the body is in equilibrium, the sum of vertical forces equals zero. Also, the sum of horizontal forces equal zero.

So, ∑Fx = 0 and ∑Fy = 0

Since Fapp acts in the negative x - direction and Ffric acts in the positive x - direction,

∑Fx = -Fapp + Ffric = 0

-Fapp + Ffric = 0

Fapp = Ffric

Also, since Fgrav acts in the negative y - direction and Fnorm acts in the positive y - direction,

∑Fy = Fnorm + (-Fgrav) = 0

Fnorm - Fgrav = 0

Fnorm = Fgrav

So, we see that the size of Fapp equals size of Ffric and the size of Fnorm equals the size of Fgrav.

So, the correct option is C

The statement which is true in this situation is C. The size of Ffric is the same as the size of Fapp.

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Answer:

160.3 g S

Explanation:

Answer:

Cl2(g) + 2 NaOH(aq) = NaCl(aq) + NaClO(aq) + H2O(l)  

Explanation:

A proton (H⁺) is transferred from the hydrochloric acid to the water molecule.

Bronsted-Lowry theory is used to classify acids and bases.

Hydrochloric acid is an acid and when it reacts with water, it transfers an H⁺ ion, according to the following equation.

HCl + H₂O ⇒ Cl⁻ + H₃O⁺

A proton (H⁺) is transferred from the hydrochloric acid to the water molecule.

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Answer:

O it's not

Explanation:

Have a great day!

Answer:

Speed =d/t. 200÷10=21÷1000=0.021 km/h

Explanation:

S=D/T

Answer:

Light from the window reflecting off the face of his watch <33

The total heat required to convert the ice to steam is 155,000 J.

The given parameters:

The heat required to raise the temperature to 0⁰C is calculated as;

[tex]Q = mc\Delta t\\\\Q_1 = 50 \times 4.184 \times (0 - (-10))\\\\Q_1 = 2092 \ J[/tex]

The  heat required to melt the ice is calculated as follows;

[tex]Q_2 = mL_f\\\\Q_2 = 50 \times 333.55 \\\\Q_2 = 16,677.5 \ J[/tex]

The heat raise the temperature to 100⁰C is calculated as;

[tex]Q_3 = 50 \times 4.184 \times (100 - 0)\\\\Q_3 = 20,920 \ J[/tex]

The  heat required to boil the water is calculated as follows;

[tex]Q_4 = mL_v\\\\Q_4 = 50 \times 2230\\\\4_4 = 111,500 \ J[/tex]

The heat raise the temperature to 120⁰C is calculated as;

[tex]Q_5 = 50 \times 4.184 \times (120 - 100)\\\\Q_5 = 4,184 \ J[/tex]

The total heat required is calculated as follows;

[tex]Q_t = Q_1 + Q_2 + Q_3 + Q_4 + Q _5 \\\\Q_t = 2092 + 16,677.5 + 20,920 + 111,500 + 4,184\\\\Q_t = 155,373.5 \ J\\\\Q_t \approx 155,000 \ J[/tex]

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The enthalpy of this reaction is -5315 KJ/mol.

The equation of the reaction is;

2C4H10(g) + 13O2(g) -----> 8CO2 (g) + 10H2O(g)

We know that the enthalpy of reaction can be obtained from the enthalpy of formation of the reactants and products as follows;

ΔHrxn = ΔHf(products) - ΔHf(reactants)

We have the following information from the question;

ΔHf C4H10 = - 125. 6 kJ/mol

ΔHf CO2 = - 393. 5 kJ/mol

ΔHf H2O = - 241. 82 kJ/mol

ΔHf O2 = 0 KJ/mol

Hence;

[(8 × (- 393. 5 )) + (10 × (-  241. 82))] - [2( - 125. 6))]

= -5315 KJ/mol

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Answer:

did u get it yet

Explanation:

Answer:

4 meters

Explanation:

4 centimeters and millimeters are too small, while 4 kilometers is too large.

Answer:

The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.

Explanation:

Answer:

1. The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart.

2. The attractive intermolecular forces between particles that tend to draw the particles together.

[tex] \huge \rm \ \blue \:{ \overbrace{ \underbrace{ \tt{ \color{red}{ \: \: \: \: \: \: answer \: \: \: \: \: \: }}}}}[/tex]

[tex] \huge \color{darkblue}P₂S_{5}[/tex]

Answer:

P2S5

Explanation:

Explanation:

At the upper left is the atomic number, or number of protons. In the middle is the letter symbol for the element (e.g., H). Below is the relative atomic mass, as calculated for the isotopes found naturally on Earth. At the very bottom is the name of the element (e.g., hydrogen).

Answer:

a hydrogen atom contains only one proton in it's nucleus, while atoms of all other elements contain more than one proton

Brainliest plzz

Answer:

0.1 M

Explanation:

(25 mL) (0.20 M) / 50 mL = 0.1 M

Molecules are formed when two or more atoms chemically bond together. In 3H₂(SO)₄, three molecules are present.

Molecules are the smallest unit present in any compound and are formed by a group of atoms. A number denoted in front of the chemical species is the coefficient that represents the number of molecules.

The coefficient present in front of the reactant or the product in a chemical reaction gives the number of the molecules present in a compound. As three is denoted in front of the sulphuric acid, hence will be the number of the molecules.

Therefore, there are three molecules present in sulphuric acid.

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Answer:

we do the best possible in our

Answer:

Ok the poprtion would look like this :  x                   23  

                                                          -----------   =     ----------

                                                            230                 100

Explanation:

So for the last fill in it could be 52.9 or 60

i hope i got it correct lol pretty sure i did