Which of the following BEST describes one of the main functions of proteins?

Answer:

[tex][H^+]=1x10^{-7}M[/tex]

Explanation:

Hello.

In this case, since the reaction between sodium hydroxide and hydrochloric acid has a 1:1 mole ratio between them:

[tex]NaOH+HCl\rightarrow NaCl+H_2O[/tex]

In order to compute the hydronium H⁺ concentration in the mixed volumes of the given solutions we first compute the moles of each reactant:

[tex]n_{NaOH}=0.750L*0.10mol/L=0.075mol\\\\n_{HCl}=0.250L*0.30mol/L=0.075mol[/tex]

As seen, since those amounts are the same, we infer all the acid and base are consumed so the pH is 7 because a neutral salt is produced, and the corresponding H⁺ concentration is:

[tex][H^+]=10^{-pH}=10^{-7}=1x10^{-7}M[/tex]

Best regards!

Answer:

D

Explanation:

It is a solid everything that is a solid is heavier

Complete question is;

What is the frequency of light emitted when the electron in a hydrogen atom undergoes a transition from energy level n=6 to level n=3?

Answer:

Frequency = 2.742 × 10^(14) s^(-1)

Explanation:

First of all, the energy of hydrogen electron from online values is;

E_n = -2.18 × 10^(-18) × (1/n²) J

n is the principal quantum number

We are told that hydrogen atom undergoes a transition from energy levels n = 3 to n = 6.

Thus, it means we have to find the difference between the electrons energy in the energy levels n = 3 to n = 6.

Thus;

E_n = E_6 - E_3

Thus;

E_n = [-2.18 × 10^(-18) × (1/6²)] - [-2.18 × 10^(-18) × (1/3²)]

E_n = (2.18 × 10^(-18)) × [-1/36 + 1/9]

E_n = 0.1817 × 10^(-18) J

From Planck expression, we can find the frequency. Thus;

E = hf

Where h is Planck's constant = 6.626 × 10^(-34) m²kg/s

Thus;

0.1817 × 10^(-18) = 6.626 × 10^(-34) × f

f = (0.1817 × 10^(-18))/(6.626 × 10^(-34))

f = 2.742 × 10^(14) s^(-1)

Answer:

the unknown substance is a protein

Explanation:

The biuret test is one of the tests for proteins. It  can be used to  detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed  leading to the appearance of a  violet color.

Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides.  It involves the formation of  a purple (violet) complex of Copper salts in alkaline solution.

Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein

Answer:

Compaction.

Explanation:

All the others are before this.

Answer:

B. are electrical signals.

Answer:

Percent error = 25%

Explanation:

Given data:

Measured density of water = 1.25 g/mL

Accepted density value of water = 1 g/mL

Percent error = ?

Solution:

Formula:

Percent error = (measured value - accepted value / accepted value) × 100

Now we will put the values in formula:

Percent error = (1.25 g/mL - 1 g/mL /1 g/mL )× 100

Percent error = (0.25 g/mL /1 g/mL )× 100

Percent error = 0.25 × 100

Percent error = 25%

Answer:

-241 kJ/mol

Explanation:

Let's consider the reaction of hydrogen with excess oxygen to form water.

2 H₂ + O₂ ⟶ 2 H₂O

When 2.16g of hydrogen reacts with excess oxygen, 258 kJ of heat are released, that is, Q = -258 kJ. Considering that the molar mass of hydrogen is 2.02 g/mol, the change of enthalpy associated with the reaction of 1.00 mol of hydrogen gas is:

ΔH° = -258 kJ/2.16 g × (2.02 g/1.00 mol) = -241 kJ/mol

Answer:

Nervous and Excretory

Explanation:

The nervous system makes you thirsty. The integumentary system makes you sweat. the integumentary system is very similar to the Excretory system.

Nervous and Excretory systems are working together in this scenario.

The nervous system makes you thirsty. The integumentary system makes you sweat. the integumentary system is very similar to the Excretory system.

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Answer:

12 pm

Explanation:

Step 1: Given data

Step 2: Calculate the kinetic energy (E) of an electron

We will use the following expression.

E = 1/2 × m × v²

E = 1/2 × 9.11 × 10⁻³¹ kg × (1.9 × 10⁸ m/s)²

E = 1.6 × 10⁻¹⁴ J

Step 3: Calculate the wavelength of an electron

We will use the following expression.

E = h × c / λ

λ = h × c / E

λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 1.6 × 10⁻¹⁴ J

λ = 1.2 × 10⁻¹¹ m

Step 4: Convert "λ" to picometers

We will use the relationship 1 m = 10¹² pm.

1.2 × 10⁻¹¹ m × (10¹² pm/1 m) = 12 pm

The wavelength of the beam of electrons is 3.8 pm.

Using the De Broglie relation;

λ = h/mv

λ  = wavelength

h = Plank's constant

m = mass of the object

v = speed of the object

Now;

λ  = ?

h = 6.6 × 10^-34 Js

m = 9.11 × 10^-31 kg

v =  1.9 × 10^8 m/s

So;

λ  =  6.6 × 10^-34 Js/ 9.11 × 10^-31 kg × 1.9 × 10^8 m/s

λ  = 6.6 × 10^-34  /1.73  × 10^-22

λ  = 3.8  × 10^- 12 m or 3.8 pm

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Answer:

Metals and Non-metals

Explanation:

Answer:

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

From the question we have

mass = 14.5 × 5

We have the final answer as

Hope this helps you

a = 7.5 m/s²

Hi there !

Newton's second law

F = m×a => a = F/m

1 N = 1kg·m/s²

a = (75kg.m/s²)/10kg

= 7.5 m/s²

Good luck !

Answer:

215.51 g of O2.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2KClO3 —> 2KCl + 3O2

Next, we shall determine the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation. This is illustrated below:

Molar mass of KClO3 = 39 + 35.5 + (16×3)

= 39 + 35.5 + 48

= 122.5 g/mol

Mass of KClO3 from the balanced equation = 2 × 122.5 = 245 g

Molar mass of O2 = 16 × 2 = 32 g/mol

Mass of O2 from the balanced equation = 3 × 32 = 96 g

From the balanced equation above,

245 g of KClO3 decomposed to produce 96 g of O2.

Finally, we shall determine the mass of O2 produced by the decomposition of 550 g of KClO3. This can be obtained as follow:

From the balanced equation above,

245 g of KClO3 decomposed to produce 96 g of O2.

Therefore, 550 g of KClO3 will decompose to produce =

(550 × 96)/245 = 215.51 g of O2.

Therefore, 215.51 g of O2 were obtained from the reaction.

Answer:

the throwing back by a body or surface of light, heat, or sound without absorbing it.

"the reflection of light"

Explanation:

i hope this helps

Answer:

Wadding is a disc of material used in guns to seal gas behind a projectile or to separate powder from shot. ... Wadding for muzzleloaders is typically a small piece of cloth, or paper wrapping from the cartridge.

Explanation:

Answer:

The acceleration will be .5 and the force will be 37.5

Have a nice day!   :)

Answer:

Hello. The answer is 37.5N.

Explanation:

If you look carfully ، every time that you add one weight the force changes 2.5N so you can do this:

[tex](2.5 \times 5) + 25 = 37.5[/tex]

The physical changes are:

The chemical changes are:

Matter can undergo 2 kinds of changes:

Let's consider the following text.

When my alarm went off at 70'clock, I hit snooze" a few times then finally got out of bed with excitement for my morning bowl of cereal. I poured the cereal and milk into my bowl. But before I even drank it, I could tell from the smell that the milk had soured! So, I decided to blend up a banana smoothie instead. I took some ice out of the freezer and grabbed the only banana that we had in the kitchen, which was covered in brown spots. My grumbling stomach needed to be satisfied before school so I didn't really care.

Just as I was sitting down to drink my smoothie my little brother came bounding into the kitchen and asked, Would you make some eggs and toast for me for breakfast?

"Ugh, sure," I said. I cut a piece of bread in half and put it in the toaster, then I cracked two eggs and whipped them with a fork. I reached for one of my mother's copper cooking pans in the cabinet and saw that it was completely tarnished! I didn't want to be blamed for this, so I ran to tell my mother right away. As I ran out of the kitchen slipped on that banana peel and it smeared all over the floor. As I lay on the floor with the wind knocked from me, I noticed that our family's plants were dying and that some water had evaporated from our fish tank. I made a mental note to take care of these things after school.

Just as I regained my breath and stood up, I heard glass breaking upstairs and my mother shrieking. I ran up the stairs, breathing heavily now. Steam was rolling out from the open bathroom door. When the steam cleared, saw why my mother had been screaming. Before me was my older sister standing in the bathroom with purple hair. I inferred from the scene that my mother had dropped a glass when she first saw her look what your sister did to her hair my mother yelled furiously I decided that I needed to get out of the house immediately, this morning was a crazy one!

A distinct smell was waiting up the stairway and I realized that my brother's toast must be burning! When reached the kitchen, my brother was happily spreading butter on his very browned toast. "I like my toast really crispy!" he said.

"Good I can't handle any more chaos this morning! I exclaimed. I grabbed my backpack headed out into the foggy morning air, and hopped on my slightly rusted bicycle to ride to school. A few minutes into my ride, my stomach grumbled and I realized that I never got a chance to drink my banana smoothie. Luckily, I had stashed a chocolate bar in my backpack yesterday. "Yes! I thought as I stopped pedaling, grabbed the chocolate and broke off a piece. As the chocolate melted in my mouth, I knew that my day was bound to get better!

The physical changes are:

The chemical changes are:

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Notice that the value 12.01 grams of natural carbon is the same as the atomic mass value (12.01 amu). It also tells us that 20.34 grams of aluminum contains exactly 6.022 x 1023 atoms of aluminum.

✅

So, the answer is A) 6.02 x 10^23 atoms

IamSugarBee

Answer:

Option A: 6.03 * 10^23 atoms

Answer:

ethyl acetate layer

Explanation:

This question tests your knowledge of the principle of solvent extraction.

In solvent extraction, there is always an organic layer and an aqueous layer. The ethyl acetate is the organic layer while the sodium bicarbonate is the aqueous layer.

A brominated aromatic compound will be extracted into the organic layer (ethyl acetate layer).

Answer:

red bricks

Explanation:

right on edg 2020

Red bricks should you use so that the area is cool in terms of temperture. Therefore, option B is correct.

Red bricks can be used in the construction of structures such as buildings, foundations, arches, pavement, and bridges. These can also be used for aesthetic purposes such as landscaping, face work, and a variety of other architectural purposes.

Traditional red bricks are saw to be more robust, and structures constructed with them are stronger than hollow block structures.Red brick can be warm, with rust or terracotta undertones. They could also be cool and more burgundy.

Thus, Red bricks should you use so that the area is cool in terms of temperture, option B is correct.

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Answer:

Explanation:

Answer:

The cohesive forces of mercury are much stronger than its adhesive forces.

Explanation:

Cohesive forces are forces that exist between the particles that compose  a substance while adhesive forces refer to forces that exist between the particles of a substance and those of another substance.

The cohesive forces in mercury far outweigh the adhesive forces between the mercury drops and glass. Hence when mercury is put into a capillary  tube, its  meniscus is convex  because cohesive forces tend to draw the liquid mercury into a drop.

Hence, the surface tension in mercury makes the mercury in the capillary tube to fall below the height of the mercury in the dish.

Answer:

Yah

Explanation:

Answer:Copper is a chemical element with the atomic number 29, and the chemical symbol Cu. Silver is also found on the periodic chart of elements, and has a chemical symbol of Ag and an atomic number of 47.

Explanation:

Both silver and copper are transition metals of d-block in periodic table they are in the same group and thus shows similar chemical and physical properties.

In periodic table, elements are classified into groups and periods. The horizontal rows are called periods and the vertical columns are called groups.

There are 18 groups and 7 periods in periodic table. Elements of the same group have same number of valence electrons and similar chemical and physical properties.

Silver, copper and gold are in 11th group of periodic table. Thus they have 9 valence electrons and exhibit similarity in properties. All these metals are good conductors and are used in electrical and optoelectronic devices.

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Answer:

Ka = 3.50x10⁻⁴

Explanation:

First, we need to convert the unit of 3.60 g/L to mol/L:

[tex] C_{C_{9}H_{8}O_{4}} = 3.60 \frac{g}{L}*\frac{1 mol}{180.16 g} = 0.0200 mol/L [/tex]

The reaction dissociation of aspirin in water is:

C₉H₈O₄  +  H₂O  ⇄  C₉H₇O₄⁻ + H₃O⁺    

0.02 - x                        x             x

The constant of the above reaction is:

[tex] Ka = \frac{[C_{9}H_{7}O_{4}^{-}][H_{3}O^{+}]}{[C_{9}H_{8}O_{4}]} [/tex]

[tex] Ka = \frac{x^{2}}{0.02 - x} [/tex]

To find Ka we need to find the value of x. We know that pH = 2.6 so:

[tex] pH = -log[H_{3}O^{+}] [/tex]

[tex] 2.6 = -log(x) [/tex]

[tex] x = 2.51 \cdot 10^{-3} M = [H_{3}O^{+}] = [C_{9}H_{7}O_{4}^{-}] [/tex]

Now, the concentration of C₉H₈O₄ is:

[tex] C_{C_{9}H_{8}O_{4}} = 0.02 - 2.51 \cdot 10^{-3} = 0.018 M [/tex]

Finally, Ka is:

[tex] Ka = \frac{[C_{9}H_{7}O_{4}^{-}][H_{3}O^{+}]}{[C_{9}H_{8}O_{4}]} = \frac{(2.51 \cdot 10^{-3})^{2}}{0.018} = 3.50 \cdot 10^{-4} [/tex]

Therefore, the Ka of aspirin is 3.50x10⁻⁴.

I hope it helps you!

Answer: The simplest and most common type is a single bond in which two atoms share two electrons. Other types include the double bond, the triple bond, one- and three-electron bonds, the three-center two-electron bond and three-center four-electron bond. ... Bonds within most organic compounds are described as covalent.

Explanation: