Magnesium oxide is 60.3% magnesium by mass. What is the mass fraction of magnesium in magnesium oxide?

a. 0.603
b. 0.397
c. 39.7
d. 60.3
e. None of these

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

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:

Oxygen is used up

Explanation:

Have an amazing day! And here is the attachment If you don't believe me. Brainliest would be nice.

Answer:

31.75 amu

Explanation:

Using Graham's equation of effusion as depicted below:

V1/V2 = √m2/√m1

Where; v1 = speed of neon gas

V2 = speed of unknown gas

m1 = molar mass of neon gas

m2 = molar mass of unknown gas

According to this question: v1 = 1.26x, m1 = 20amu, v2 = 1x, m2 = ?

Hence,

1.26x/1x = √m2/√20

1.26/1 = √m2/4.472

√m2 = 4.472 × 1.26

√m2 = 5.635

m2 = 5.635²

m2 = 31.75 amu

Therefore, the molar mass of the unknown gas is 31.75 amu.

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:

Ka = 4.70x10⁻⁴M

Explanation:

The general dissociation of a weak acid, HX, is:

HX(aq) ⇄ H⁺(aq) + X⁻(aq)

And Ka is written as:

Ka = [H⁺] [X⁻] / [HX]

Where [] represents the molar concentration in equilibrium of each specie.

The equilibrium is reached when X of HX is dissociate in X H⁺ and X X⁻, that is:

[HX] = 0.0129M - X

[H⁺] = X

[X⁻] = X

As pH = -log [H⁺]:

10^-pH = [H⁺] = X  = 2.239x10⁻³M

Solving:

[HX] = 0.0129M - 2.239x10⁻³M = 0.01066M

[H⁺] = 2.239x10⁻³M

[X⁻] = 2.239x10⁻³M

Ka = [H⁺] [X⁻] / [HX]

Ka = [2.239x10⁻³M] [2.239x10⁻³M] / [0.01066M]

Answer:

d one is correct answer

Compounds are substances made by chemical bonding between elements and molecules. CH₃-CH₂-OCH(CH₃)₂ has the lowest boiling point. Thus, option D is correct.

The boiling property and the functional group determine the property of the organic molecule. The boiling property of the molecules is defined by the intermolecular forces, the number of carbons (molecular mass), and branching.

The presence of functional groups like bonds (double and triple), carbonyl, halogens, and alcohol increases the boiling point of the substances. The given substances are:

The order of boiling point is given as:

hexane (alkane)> ethoxyethane (ether)> methyl propyl ether (ether)> Pentan-1-ol (alcohol) > 2-ethoxypropane (ketone).

Therefore, option D. 2-ethoxypropane (ketone) has the least boiling point.

Learn more about boiling point, here:

https://brainly.com/question/10404354

#SPJ2

Answer:

c. 3

Explanation:

Dicholorination of tertiary alkane ( i.e. isobutane) is a halogenation reaction which makes it possible to replace the alkyl functional group with halogenated chlorine.

When Isobutane is subjected to free radicals chlorination, three distinct dichlorination can be formed.

The mechanism of the formation of these products can be seen in the image attached below.

Answer:

Kc is 18.478

Explanation:

Here we want to calculate Kc given Kp

The equation that links both is given as follows;

Kc = Kp/(RT)^Δn

where Kp = 0.0133

R is molar gas constant = 0.0821 L.atm/mol.k

T is temperature in kelvin = 181 + 273 = 454K

Δn is the change in number of moles between products and reactants = 2-4 = -2

Substituting these values, we have;

Kc = 0.0133/(0.0821 * 454)^-2

Kc = 18.478

4.47 x 10- 4 spook/ L is the value of Kc for the response N2( g) 3H2( g) 2NH3( g) at 181 °C.

Given

the chemical equation N2(g)+3H2(g)↽−−⇀2NH3(g) is Kp=0.0133 at 181 ∘C.

To Find

the value of Kc for the reaction at 181 ∘C.

Solution

In order to determine the value of Kc for the response N2( g) 3H2( g) 2NH3( g) at 181 °C, we can use the relationship between Kp and Kc.

This equation relates Kp with Kc

Kc = Kp( RT) n

where

Partial pressures are used to express Kp, the equilibrium constant.

In molar attention, Kc represents the equilibrium constant.

The gas constant, or R, is0.08206 L atm/ K spook.

The temperature in Kelvin is T.

The stoichiometric measure n is the difference between the aggregate of the gassy products' and gassy reactants' stoichiometric portions.

Then are the data

Δn = ( 2-( 1 3)) = -2

still, we get

If we substitute the values handed.

The formula for 0.0133 is Kc(0.08206 L/ atm/ Kmol *( 181 273) K)- 2.

When we simplify and find Kc, we gain

Kc equals4.47 x 10- 4 spook/L.

thus,4.47 x 10- 4 spook/ L is the value of Kc for the response N2( g) 3H2( g) 2NH3( g) at 181 °C.

For more similar answer refer

https://brainly.com/question/18484878

Answer:

Explanation:

pituitary gland

Answer:

B

Explanation:

The pituitary gland is a pea-sized structure that is attached to the undersurface of the brain by a thin stalk.

Answer:

The table feels cold because it is at a lower temperature than the students' hands, and thermal energy is being pulled into the table.

Explanation:

The thermal conductivity of the table is low and so it feels cold.

Thermal conductivity is the measure of the ability of a material to conduct heat.

The rate at which heat is transported by conduction through a material's unit cross-section area when a temperature gradient exits perpendicular to the area is known as thermal conductivity.

Thermal energy is the energy contained within a system that accounts for the temperature of the system.

The human body cannot measure the temperature of any object but it can feel the difference in the temperature.

If one body is at 20 degrees Celsius, and an object is at 30 degrees Celsius, then the body will feel hot when the object is touched.

Similarly, when the students touched the table, the conductivity of the wood is very low, and it feels cold.

The thermal energy of the table is lower than the thermal energy of the body.

To know more about Thermal Conductivity

https://brainly.com/question/7643131

#SPJ6

Answer:

There are three basic types of chemical formula, the empirical formula, the molecular formula, and the structural formula.

Answer:

[tex]m_{Ag}=2,265.9g[/tex]

Explanation:

Hello!

In this case, since the definition of entropy in a random mixture is:

[tex]\Delta S=-n_TR\Sigma[x_i*ln(x_i)][/tex]

For this silver-gold mixture we write:

[tex]\Delta S=-(n_{Au}+n_{Ag})R\Sigma[\frac{n_{Au}}{n_{Au}+n_{Ag}} *ln(\frac{n_{Au}}{n_{Au}+n_{Ag}} )+\frac{n_{Ag}}{n_{Au}+n_{Ag}} *ln(\frac{n_{Ag}}{n_{Au}+n_{Ag}} )][/tex]

By knowing the moles of gold:

[tex]n_{Au}=100g*\frac{1mol}{197g} =0.508mol[/tex]

It is possible to write the aforementioned formula in terms of the variable [tex]x[/tex] representing the moles of silver:

[tex]20\frac{J}{mol}=-(0.508+x)8.314\frac{J}{mol*K} \Sigma[\frac{0.508}{0.508+x} *ln(\frac{0.508}{0.508+x} )+\frac{x}{0.508+x} *ln(\frac{x}{0.508+x} )][/tex]

Which can be solved via Newton-Raphson or a solver software, in this case, I will provide you the answer:

[tex]x=n_{Ag}=21.0molAg[/tex]

So the mass is:

[tex]m_{Ag}=21.0mol*\frac{107.9g}{1mol}\\ \\m_{Ag}=2,265.9g[/tex]

Best regards!

Answer:

4.5 × 10⁻⁹

Explanation:

Step 1: Write the reaction for the solution of CaCO₃

CaCO₃(s) ⇄ Ca²⁺(aq) + CO₃²⁻(aq)

Step 2: Convert the solubility of CaCO₃ from g/L to mol/L

We will use the following conversion factors:

[tex]\frac{0.00067 gCaCO_3}{100mLSol} \times \frac{1molCaCO_3}{100.09gCaCO_3} \times \frac{1000mLSol}{1LSol} = 6.7 \times 10^{-5} M[/tex]

Step 3: Calculate the solubility product constant (Ksp)

To relate Ksp and the molar solubility (S), we need to make an ICE chart.

        CaCO₃(s) ⇄ Ca²⁺(aq) + CO₃²⁻(aq)

I                               0                0

C                            +S               +S

E                              S                 S

The solubility product constant is:

Ksp = [Ca²⁺].[CO₃²⁻] = S² = (6.7 × 10⁻⁵)² = 4.5 × 10⁻⁹

Answer:

THE ANSWER IS D UR WELCOME.

Explanation:

Answer:

5Ns

momentum= mass *velocity

=1*5

=5Ns

Analysing the Question:

We are given the balanced equation:

C₆H₁₂O₆ + 6O₂→ 6CO₂ + 6H₂O

from this equation, we can say that: for every 1 mole of Glucose, we need 6 moles of Oxygen

Moles of Glucose used in the reaction:

Molar mass of Glucose = 180 grams / mol

Given mass of Glucose = 1 gram

Mole of Glucose = Given mass / Molar mass

Moles of Glucose = 1 / 180 moles

Mass of Oxygen required:

We know that for every mole of Glucose, we need 6 moles of Oxygen

So, for 1/180 moles of Glucose, we need 6 / 180 = 1 / 30 moles of Oxygen

Mass of 1 / 30 moles of Oxygen:

Mass = Molar mass * number of moles

Mass of Oxygen = 32 * 1/30

Mass of Oxygen  = 32 / 30

Mass of Oxygen = 1.06 grams

Answer:

Options a,b, c and d are correct

Explanation:

From the diagram attached in the picture below, They both have steroid nucleus since they have functional groups (such as the methyl and the ketone groups) that are spatially attached. It can also be deduced that both structures have three (3) ketone groups (CO/C=O), two (2) methyl groups (CH₃) and two (2) hydroxyl groups (OH). Hence, options a, b,c and d are correct.

However, cortisone has one (1) double bond while prednisone has two (2) double bonds.

Answer:

D

Explanation:

Photosphere is the layer where sunspots form.

Photosphere is the layer where sunspots form.

The Sun is made up of layers of material, like a baseball or rubber band ball. The photosphere is the lowest layer of the solar atmosphere. It is essentially the solar "surface" that we see when we look at the Sun in "white" (i.e. regular, or visible) light.

Like the Sun, our planet, Earth, is made up of layers, too. The thickest or most dense material on the Earth is in the very middle of our planet -- the core.

The thinnest is at the very top of our atmosphere - right next to outer space. The same is true of the Sun. But, the layers in the Sun and the Earth are much different.

Therefore, Photosphere is the layer where sunspots form.

To learn more about Photosphere, refer to the link:

https://brainly.com/question/29127538

#SPJ5

Answer:

C, Movement

Explanation:

Answer:

Explanation:

A solution with a pH value of 7 is neutral i.e neither acidic nor alkaline. A solution with a pH less than 7 is said to be acidic, while one with a pH value more than 7 is alkaline. Acidity increases as the value decrease below 7, while alkalinity increases as the value increase about 7.

Given that H2A is a diprotic weak acid have pKa values of 5.0 ad 9.0, it will undergo dissociation in the solution as:

NOTE: These reactions are reversible reactions.

[tex]\mathbf{H_2A \to H^+ + HA^- \ \ \ pKa = 5.0}[/tex]

[tex]\mathbf{HA^- \to H^+ +A^{2-} \ \ \ pKa = 9.0}[/tex]

Thus;

The primary species is HA⁻

The secondary species is A²⁻

Answer:

to find out how somethings work

Explanation:

Answer:

Doing experiments is good because when you try these possibilities you can learn about something that you've tried or see why this experiment didn't really work. It also helps you understand that  not everything you try will work. that's why we experiment.

Explanation:

Hope this helps:)

Answer:

The given reaction has been the symbolization for replacement reaction. Thus, option D is correct.

The given general reaction has been:

[tex]\rm AB\;+\;CD\;\rightarrow\;AD\;+\;CB[/tex]

In the given reaction, there has presence of compound AB and CD. The reaction between the two results in the formulation of AD and CB. In the reaction, the B has been more attracted by C and forms bond with C by replacing D.

In the same way, A has been more attracted with D and forms bond with D replacing C.

The type of reaction in which the more reactive element replaces the less reactive element has been termed as replacement reaction. Thus, the given reaction has been the symbolization for replacement reaction. Thus, option D is correct.

For more information about replacement reaction, refer to the link:

https://brainly.com/question/8625202

Answer:

100 joules​

Explanation:

The mechanical energy (M.E) of an object describes the objects ability to do work. The mechanical energy encompasses the object's energy due to its position (potential energy) and its energy due to motion (kinetic energy).

Therefore,

M.E = K.E + P.E

According to this question, potential energy (P.E) of the roller coaster is 50J and the kinetic energy (K.E) is also 50J. Hence, the mechanical energy (M.E) is

M.E = 50J + 50J

M.E = 100J

If the P.E and K.E of a roller coaster is 50 Joules respectively, the mechanical energy of the roller coaster is 100 Joules.

Given the following data:

To find the mechanical energy of the roller coaster:

The mechanical energy of a physical object or body is the total sum of the potential energy (P.E) and kinetic energy (K.E) possessed by an object.

Mathematically, mechanical energy is given by the formula;

Substituting the given parameters into the formula, we have;

[tex]M.E = 50 + 50[/tex]

Mechanical energy (M.E) = 100 Joules.

Therefore, the mechanical energy of the roller coaster is 100 Joules.

Read more: https://brainly.com/question/23153766

Answer:

make an observation that describes a problem

Explanation:

Answer:

The first step in the Scientific Method is to make objective observations.

Explanation:

....-

Answer:

1.52g NaHCO3 were in the original mixture.

Mass percent: 64.1%

Explanation:

When NaHCO3 heats it descomposition occurs as follows:

2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g).

The loss in mass is because of the evaporization of CO2 and H2O. As both are in the same porportion, its molar mass is the sum of both compounds (44g/mol + 18g/mol = 62g/mol)

Loss in mass: 74.80g - 74.24g = 0.56g.

In moles:

0.56g * (1mol / 62g) = 0.00903 moles of gas.

As 1 mole of the gases comes from 2 moles of NaHCO3:

Moles NaHCO3:

0.00903 moles of gas * (2 moles NaHCO3 / 1 mole gas) = 0.018 moles NaHCO3.

In grams (Molar mass NaHCO3: 84g/mol):

0.018 moles NaHCO3 * (84g / mol) = 1.52g NaHCO3 were in the original mixture.

The mass of the mixture was:

74.80g - 72.428g = 2.372g

That means mass percent of NaHCO3 is:

(1.52g /  2.372g) * 100 =  64.1%

Answer:

One mole of Al weighs 27g.

2.5 moles of Al weigh 67.5g.

Answer:

Axial

Explanation:

In the most stable conformation of Cis-3-tert-Butylcyclohexanol, the tert-butyl group is at equatorial position and the alcohol group is in the axial position.

If the tert-butyl group is placed in equatorial position, repulsions are minimized. The bulkier the group, the greater the energy difference between the axial and equatorial conformers. Hence for a ring having a bulky substituent, such bulky substituent is better placed in the equatorial position.

The energy difference between the conformers of Cis-3-tert-Butylcyclohexanol is so high that the compound is almost "frozen" in a conformation  where the tert-butyl groups are equatorial and the -OH groups are axial. This conformer is more stable by 24 KJ/mol.

Cis-3-tert-Butylcyclohexanol has the molecular formula of [tex](\rm C_{10}H_{20}O)[/tex]. The alcohol group in the compound is found at the axial position.

In the compound Cis-3-tert-Butylcyclohexanol alcohol is the functional group present at the axial position and tert-butyl group at the equatorial position of the compound.

Tert-butyl group at the equatorial position minimizes the repulsive forces and are bulky groups, the position of the bulkier groups at the equatorial positions are better as the energy differences will be large.

The difference in the energy of the conformers of the compound is high and the conformation of the compound remains as it is.

Therefore, tert-butyl groups are at equatorial and the alcohol groups are at axial.

Learn more about equatorial and axial positions here:

https://brainly.com/question/10696788