Can someone help me answer this please

Answer: The amino acid that has a positively charged R group are LYSINE and ARGININE.

Explanation:

AMINO ACIDS are the basic structural units of proteins. Each amino acid contains an amino group ( -NH2) and a carboxyl group (-COOH) in its molecule. The carbon atom of amino acid to which the functional groups are attached is know as the alpha-carbon. In neutral solution, amino acids are mainly in the form of dipolar ions. Amino acids can be prepared through hydrolysis of protein by boiling with dilute hydrochloric acid.

Amino acids can be classified according to the chemical properties of its side chain (R group) at pH 7, these include:

--> Amino acids with POSITIVELY CHARGED R group

--> Amino acids with negatively charged R group

--> Amino acids with neutral polar R group

--> Amino acids with nonpolar aliphatic R group.

Amino acids with POSITIVELY CHARGED R group are those amino acids that has side chains which contain nitrogen and resemble ammonia, which is a base. Their pKa's are high enough that they tend to bind protons, gaining a positive charge in the process. Example include LYSINE and ARGININE.

Answer:

aasjajiakjka

Explanation:

Answer:

Adding ammonium nitrate to water turns the mixture cold and is a good example of an endothermic chemical reaction!

Answer:

i think its c [everything is so blury]

Explanation:

Answer:1.b 2.A (i think it might be c) 3 (i have no clue) 4.(no clue) Sorry i only got 1 and 2 witch i think are right its been a while sense i have done this....

Explanation:

Answer:

Selective serotonin reuptake inhibitors (SSRIs)

Explanation:

A synaptic cleft is a space that separates two neurons thereby forming a junction between two or more neurons. The synaptic cleft helps in the transfer of nerve impulse from one neuron to the other.

5-HT is found in the enteric nervous system located in the gastrointestinal tract and it helps in modulating cognition, memory, sleep, and numerous physiological processes.

Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine and citalopram are used to increase the level of 5-HT in the synaptic cleft by inhibiting its reuptake into the presynaptic terminal.

Answer:

C. The mass stays the same because the total number of atoms does not change

Explanation:

According to the law of conservation of matter/mass, matter cannot be created nor destroyed, hence, the amount of matter in the reactants must be the same amount in the products.

Using the photosynthetic reaction as a case study, carbon dioxide (CO2) and water (H2O) are the compounds that go into the reaction (reactants) while glucose and oxygen (O2) are the products of the reaction.

Using the law of conservation of matter to explain, the total mass of both the reactants and products stays the same because the total number of atoms does not change i.e. if 6 atoms of Carbon starts the reaction, 6 atoms of carbon will end it.

Answer:

(a) Pair 1: H₂S and HS⁻

    Pair 2: NH₃ and NH₄⁺

(b) Pair 1: HSO₄⁻ and SO₄⁻

    Pair 2: NH₃ and NH₄⁺

(c) Pair 1: HBr and Br⁻

    Pair 2: CH₃O⁻ and CH₃OH

(d)  Pair 1: HNO₃ and NO₃⁻

     Pair 2: H₃O⁺

Explanation:

When an acid loses its proton (H⁺), a conjugate base is produced.

When a base accepts a proton (H⁺), it forms a conjugate acid.

(a) H₂S is an acid. When it loses a proton, it forms the conjugate base HS⁻.

    NH₃ is a base. When NH₃ gains a proton, it forms the conjugate acid NH₄⁺

(b) The acid HSO₄⁻ loses a H⁺ ion and forms the conjugate base SO₄²⁻.

     The base NH₃ accepts a H⁺ ion to form the conjugate acid NH₄⁺.

(c) HBr is an acid. When loses the H⁺ ion, it forms the conjugate base Br⁻.

   CH₃O⁻ accepts a H⁺ ion to form the conjugate acid CH₃OH.

(d) HNO₃ loses a proton to form the conjugate base NO₃⁻.

    H₂O gains a proton to form the conjugate acid H₃O⁺.

Answer:

D

Explanation:

there is no other answer choice that does not move. This is a fool-proof question because all the other answer choices contain movement except the butterfly resting

Answer: The final temperature will be [tex]52.74^oC[/tex]

Explanation:

Calculating the heat released or absorbed for the process:

[tex]q=m\times C\times (T_2-T_1)[/tex]

In a system, the total amount of heat released is equal to the total amount of heat absorbed.

[tex]q_1=-q_2[/tex]

OR

[tex]m_1\times C\times (T_f-T_1)=-m_2\times C\times (T_f-T_2)[/tex] ......(1)

where,

C = heat capacity of water = [tex]4.184J/g^oC[/tex]

[tex]m_1[/tex] = mass of water of sample 1 = 100.0 g

[tex]m_2[/tex] = mass of water of sample 2 = 71.0 g

[tex]T_f[/tex] = final temperature of the system = ?

[tex]T_1[/tex] = initial temperature of water of sample 1 = [tex]27^oC[/tex]

[tex]T_2[/tex] = initial temperature of the water of sample 2 = [tex]89.0^oC[/tex]

Putting values in equation 1, we get:

[tex]100.0\times 4.184\times (T_f-27)=-71.0\times 4.184\times (T_f-89)\\\\171T_f=9019\\\\T_f=\frac{9019}{171}=52.74^oC[/tex]

Hence, the final temperature will be [tex]52.74^oC[/tex]

Answer:

While Mg(OH)2 is practically insoluble, a certain amount of Mg(OH)2 dissociates into ions when put in water. ... As HCl is added to the beaker containing milk of magnesia, the H+ ions from the HCl react with the OH– ions (those that are actually in solution from the Mg(OH)2) according to Equation 3 below.

Answer:

20,8ml  NaCl 6M

Explanation:

C1V1 = C2V2

Answer:

(d)

Explanation:

Carbonyl group can be the placement of kerosene sugar

Answer:

electrophilic addition and

nucleophilic addition.

Answer:

the two types of addition compoundsare:

1.electrophilic addition

2. nucleophilic addition.

Answer:

Classify each structure according to its functional class.

Compound A contains a carbonyl bonded to two alkyl groups.

Compound B contains an oxygen bonded to two alkyl groups.

Compound C contains a carbonyl bonded to propyl and N H C H 3.

Compound D is a nitrogen bonded to three alkyl groups.

Explanation:

Compound A contains a carbonyl bonded to two alkyl groups.

-C=O group is called a carbonyl group.

If it is present between two alkyl groups then, it is a ketone.

Compound B contains oxygen bonded to two alkyl groups.

Compound B is an example of an ether molecule.

Compound C contains a carbonyl bonded to propyl and N H C H 3.

Compound C is C3H7-CO-NHCH3 which is an amide molecule.

Compound D is nitrogen bonded to three alkyl groups.

This is an example of a tertiary amine group.

Answer:

Explanation:

This is because, Blue color highest frequency of energy after Violet and Indigo.

Answer:

which language is this please tell me

Answer:

C8H18 + 25/2O2 ----> 8CO2 + 9H2O

Explanation:

2,3,3-trimethylpentane has the molecular formula C8H18.

The general formula for the combustion of an alkane is;

CnH2n+2 + 3n+1/2O2 ----->nCO2 + (n+1)H2O

In writing a balanced chemical reaction equation, the number of atoms of each element on the left hand side of the reaction equation must be the same as the number of atoms of the same element on the right hand side of the reaction equation.

For C8H18, the balanced chemical reaction equation for combustion is;

C8H18 + 25/2O2 ----> 8CO2 + 9H2O

Answer:

14.9 g

Explanation:

Step 1: Write the balanced equation

C₄H₁₀ + 6.5 O₂ ⇒ 4 CO₂ + 5 H₂O

Step 2: Calculate the moles corresponding to 9.57 g of C₄H₁₀

The molar mass of C₄H₁₀ is 58.12 g/mol.

9.57 g × 1 mol/58.12 g = 0.165 mol

Step 3: Calculate the moles of H₂O produced from 0.165 moles of C₄H₁₀

0.165 mol C₄H₁₀ × 5 mol H₂O/1 mol C₄H₁₀ = 0.825 mol H₂O

Step 4: Calculate the mass corresponding to 0.825 mol of H₂O

The molar mass of H₂O is 18.02 g/mol.

0.825 mol × 18.02 g/mol = 14.9 g

Answer:

Amount of reactant after four hours = 4,26 grams

Explanation:

Suppose y denotes the amount of reactant at the time (t)

The given function:

[tex]\dfrac{dy}{dt} = -0.7 y[/tex]

[tex]\dfrac{dy}{y} = -0.7 dt[/tex]

Taking integral on both sides

㏑(y) = -0.7t + c¹

[tex]e^{In(y)}= e^{-0.7t + c^1}[/tex]

[tex]y(t) = Ce ^{-0.7t}[/tex]

At t = 0 ; y (t) = 70

∴

[tex]70 = Ce^{-0.7(0)}[/tex]

C = 70

As such; [tex]\mathtt{y(t) = 70 e^{-0.7*t}}[/tex]

After four hours, the amount of the reactant is:

[tex]\mathtt{y(t) = 70 e^{-0.7*4}}[/tex]

[tex]\mathtt{y(t) = 70 e^{-2.8}}[/tex]

[tex]\mathtt{y(t) = 4.26}[/tex]

Amount of reactant after four hours = 4,26 grams

Answer:

as in shapes

Explanation:

Answer:

[tex]X=75\%[/tex]

Explanation:

From the question we are told that:

Concentration [tex]C_1=17.50ppb[/tex]

Volume [tex]v=9mL[/tex]

Spike Volume [tex]V_s=1.00mL[/tex]

spike Conc [tex]C_2=2.29 ppb[/tex]

Analysis Conc [tex]C_s=15.93 ppb[/tex]

Generally the equation for  percent recovery is mathematically given by

 [tex]X=\frac{C_s'-C_1'}{C_2'}[/tex]

Where

Concentration of spiked sample C_s'

 [tex]C_s'=C_s*(v+v_s)[/tex]

 [tex]C_s'=15.92*(9+1)[/tex]

 [tex]C_2=159.2[/tex]

Concentration of unspiked sample C_1'

 [tex]C_1'=17.50*9mL[/tex]

 [tex]C_1'=157.5[/tex]

Concentration of spike sample C_2'

 [tex]C_2=2.29*1[/tex]

 [tex]C_2=2.29[/tex]

Therefore

 [tex]X=\frac{159.2-157.5}{2.29}[/tex]

 [tex]X=75\%[/tex]

Answer:

answer is b. : It has been balanced by using the half-reaction method.

Explanation:

edge 2021

Answer:b

Explanation:cuz it is

Answer:

A. Wax drips down the side of a lot candle.

Explanation:

The chemical change from solid to liquid. This is a combustion reaction, so carbon dioxide gas and water vapour is also produced but you can't see them

Answer:

A. Wax drips down the side of a lot candle.

Explanation:

Answer:

the answer would be 6.720

Simply subtract the combined mass by the mass of the beaker.

The answer has 3 decimal places because the least amount of decimal places in the equation is 3.

Answer:

The quantity of  heat required to raise the  temperature of 500 g of  iron by 2°C is 500 J.

Explanation:

Calorimetry is responsible for measuring the amount of heat generated or lost in certain physical or chemical processes.

The sensible heat of a body is the amount of heat received or transferred by a body when undergoing a temperature variation (Δt) without there being a change in physical state (solid, liquid or gaseous).

Its mathematical expression is the fundamental equation of calorimetry. This is:

Q = c * m * ΔT

where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.

In this  case:

Replacing:

Q= 500 [tex]\frac{J}{kg*C}[/tex] *0.500 kg*2 C

Solving:

Q= 500 J

The quantity of  heat required to raise the  temperature of 500 g of  iron by 2°C is 500 J.

Answer:

Scandium

Explanation:

Mendeleev played an important role in the development of the modern periodic table. His periodic table was filled with gaps. He said that these gaps were elements that were yet to be discovered. He rightly predicted many elements which have now been discovered and fitted in their proper places in the periodic table.

He used the prefix ''eka'' to refer to elements whose properties were alike but were yet to be discovered at that time.

The compound named ekaboron which he predicted to have an atomic weight between 65 (zinc) and 75 (arsenic) with a valence similar to aluminum was later discovered in 1879 and properly named scandium.

Answer:

1) True

Explanation: