Rupert had three substances. A brown substance was a liquid at room
temperature. He hit each of the other two with a hammer. A blue crystal
cracked but did not break. A silver substance flattened but did not crack.
Which two statements could be true?
A. The brown substance is ionic
B. The silver substance is ionic
C. The brown substance is molecular
D. The blue substance is ionic

Answer:

make an observation that describes a problem

Explanation:

Answer:

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

Explanation:

....-

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:

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.

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Answer:

5Ns

momentum= mass *velocity

=1*5

=5Ns

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.

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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:

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.

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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:

[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:

C

Explanation:

It will be the same. That's what moving down a column means. The properties are going to be quite similar.

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.

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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:

THE ANSWER IS D UR WELCOME.

Explanation:

Answer:

Creativity can help scientists by leading them to ask more questions about the natural world.

Explanation:

Beacause they use creativity to make up questions about the natural world.

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 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.

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Answer:

–23000 Calories.

NOTE : The negative sign indicates that heat has been loss to the student back.

Explanation:

The following data were obtained from the question:

Mass (M) of water = 575 g

Initial temperature (T1) = 80 °C

Final temperature (T2) = 40 °C

Heat (Q) transferred =.?

Next, we shall determine the change in temperature (ΔT).

This is illustrated below:

Initial temperature (T1) = 80 °C

Final temperature (T2) = 40 °C

Change in temperature (ΔT) =?

Change in temperature (ΔT) = T2 – T1

Change in temperature (ΔT) = 40 – 80

Change in temperature (ΔT) = –40°C

Finally, we shall determine the heat transferred. This can be obtained as follow:

Mass (M) of water = 575 g

Change in temperature (ΔT) = –40°C

Specific heat capacity (C) of water = 1 Cal/g°C

Heat (Q) transferred =.?

Q = MCΔT

Q = 575 × 1 × –40

Q = –23000 Calories

NOTE : The negative sign indicates that heat has been loss to the student back.

Answer:

C, Movement

Explanation:

Answer:

A

Explanation:

B- is dna related

C i dunno

and d is about protein so that leaves A

Answer:

The mass of Ca²⁺ present in the water sample =  13.23 mg/L.

The mass for the Mg²⁺ in the water sample =  25.06 mg/L.

Explanation:

We are given the following set of values which are going to aid in solving this particular question/problem. Thus, the parameters or data or information is given below:

First part:

Total volume of the water sample =  100.00-mL water sample, volume of the EDTA solution = 10.87 mL, the concentration of the EDTA solution = 0.0125 M, the adjusted pH of the water sample with  = 10.

Second part:

Total volume of the water sample =  100.00-mL water sample, volume of the EDTA solution = 2.63 mL and the adjusted pH of the water sample with  = 12.

Thus, the first thing to do now is to determine the number of moles of the EDTA solution in Ca²⁺ titration which is; 0.0125 x 0.00263 = 3.30 x 10⁻⁵ moles.

The mass of Ca²⁺ present in the water sample = [3.30 x 10⁻⁵ moles × 40.08 ] ÷ 100 mL. =  13.23 mg/L

In 100mL, the number of moles of Mg²⁺ = (total number of moles of EDTA solution used ) - ( number of moles of the EDTA solution in Ca²⁺ titration).

Also, The number of moles of Mg²⁺ = ( 0.0125  x 0.01087) - (3.30 x 10⁻⁵ moles.) =  1.031 x 10⁻⁴ moles.

The mass for the Mg²⁺ in the water sample =  1.031 x 10⁻⁴ moles  x  24.305/0.1 = 25.06 mg/L.

Answer:

One mole of Al weighs 27g.

2.5 moles of Al weigh 67.5g.

Order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing.

Answer:

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

Calcium (Ca) is in group 2 and period 4 on the periodic table be because Calcium has 2 valence electrons and 4 electron shell. Thus, calcium is a metal like all other group 2 element.

The correct answer to the question is Option C. Calcium, like all group 2 elements, is reactive and a solid at room temperature.

Calcium is a group 2 element majorly because it has 2 valence electrons. It is also in period 4 because it has 4 electron shells.

Being a group 2 element, calcium is a solid at room temperature and also reactive. All elements in the group 2 are metals.

There are other elements in period 4 which are not solid. For example krypton is an element in period 4 and it is a gas and not reactive.

From the above information, we can conclude that the correct answer to the question is:

Option C. Calcium, like all group 2 elements, is reactive and a solid at room temperature.

See attached image

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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:

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.