If a brownie that measures 15 cm * 7 cm * 7 cm and has a density of 2.3 g/cm^ ^ 3 is cut in half what will happen to the density of the brownie ? *

Answer:

Scientific models are used to explain phenomena that can not be experience directly and it is also used for prediction.

Explanation:

An example of idea model is the Eistein equation.  An idea model shows how things interact together to produce a particular result.

An example of physical model is the solar system.

Computer model is used to predict long term events and an example of this is computer simulations.

Answer:

0.384928 J/g°C

Explanation:

The formula for Specific Heat (C)

= q/m × ∆t

Where q = Heat energy required to heat the compound (in joules)

m = mass of the compound (sample)

∆t = Change in temperature

In the question, we are given the following values.

m = 5.0g

∆t = Change in temperature = 75°C - 25°C

= 50°C

q = Heat energy = 23 cal

We have to convert to joules

One calorie is equal to 4.184 joules.

1 Cal = 4.184 joules

23 Cal =

23 × 4.184 joules

= 96.232 joules

Specific Heat (C) of copper

= 96.232 J /(5g × 50°C)

= 96.232J / 250

= 0.384928 J/g°C

Therefore, the Specific Heat of Copper is 0.384928 J/g°C

Answer:

a number should be rounded up it is 5 or higher

Answer:

option b is correct

Explanation:

when the temperature of liquid solid and gases increases the kinetic energy of their molecules increases but when the temperature of liquid solid or gases  decreases then kinetic energy of the molecule decreases

Answer:

B. Decreased kinetic energy of the molecules

Explanation:

The average kinetic energy of molecules determines the temperature of a substance.

Hotter objects

have faster-moving particles and higher temperatures

Temperature measures the averages because moving particles can absorb/release heat with each collision as heat is converted to kinetic energy and back.

Chemistry V22 flvs 6.01

The molar mass of H2S is greater than the molar mass of NH3, making the velocity and effusion rate of NH3 particles faster.

Effusion rate is inversely proportional to molar mass. NH3 will have a higher average molecule velocity, so it will diffuse faster and will reach the other side of the room more quickly.

The concentration gradient, or the rise or fall in concentration from one site to another, the amount of surface area available for diffusion, and the distance the gas particles must travel all affect the diffusion rate.

The effusion of gas molecules into a vacuum through a small hole, as a pinhole in a balloon, is a process that involves movement of gaseous species comparable to diffusion.

Therefore, The molar mass of H2S is greater than the molar mass of NH3, making the velocity and effusion rate of NH3 particles faster.

To learn more about Diffusion, refer to the link:

https://brainly.com/question/20843145

#SPJ7

Answer:

0.035 m CH3CH2CH2OH

Explanation:

We know that freezing point is a coligative property hence it depends on the number of solute particles present.

Covalent substances do not break up into ions, hence they do not produce many particles in solution unlike ionic substances. Hence, ionic substances have a far higher freezing point than covalent molecules.

For this reason, 0.035 m CH3CH2CH2OH has the lowest freezing point.

Answer:

7.376 × 10^9 people

Explanation:

yes

Answer:

d) BaF2

Explanation:

The compound which is more soluble in an acidic solution than in a neutral solution is shown below:-

First we will compare acidic with Neutral

[tex]acidic \rightarrow H+ ions[/tex]

So,

[tex]PbBr2 \rightarrow Pb+2 + 2Br-[/tex]

[tex]BaF2 \rightarrow Ba+2 + 2F-[/tex]

[tex]AgI \rightarrow Ag+ + I-[/tex]

[tex]CuCl \rightarrow Cu+ + Cl-[/tex]

Now, when we add H+ ions, so it will be

[tex]BaF2 \rightarrow Ba+2 + 2F-[/tex]

[tex]F- + H2O <-> HF + OH-[/tex]

Then it will reduces F-, as BaF2 begin to form more aqueous ions, so, it will rises the solubility

Answer:

False

Explanation:

Temperature is the measure of the amount of kinetic energy in a substance.

It is commonly assumed that temperature measures the amount of heat, because it is commonly associated with the weather or checking for fevers.

However, temperature is truly a measure of the average kinetic energy of a substance.

Answer:

Temperature is the measure of average kinetic energy in a substance.but heat is also a form of kinetic energy so i think its also true to say that temperature is a measure of heat in a substance.

Explanation:

Answer:

Yes.

Explanation:

Substances are made up of matter or matter are made up of tiny molecules or atoms that occur naturally or some are synthetic or man made.

All matter are made up of substances called elements and each elements have its own physical and chemical properties and cannot be broken easily by ordinary chemical reactions.

Of all the 118 elements only 92 occur naturally and 26 are man made or synthetic which are made in the laboratories.

Answer:

a) Insoluble

b) Soluble

c) Insoluble

d) Insoluble

e) Soluble

f) Soluble

Explanation:

Answer:

Explanation:

The definition of acids and bases by Arrhenius Theory  was modified and extended by  Bronsted-Lowry.

Bronsted-Lowry defined acid as a molecule or ion which donates a proton while a base is a molecule or ions that accepts the proton. This definition can be extended to include acid -base titrations in non-aqueous solutions.

In this theory, the reaction of an acid with a base constitutes a transfer of a proton from the acid to the base.

From the given information:

[tex]\mathsf{HCN _{(aq)} + H_2O_{(l)} \to CN^{-}_{(aq)} + H_3O_{(aq)}}[/tex]

From above:

We will see that HCN releases an H⁺ ion, thus it is a Bronsted-Lowry acid

[tex]H_2O[/tex] accepts the H⁺ ion ,thus it is a Bronsted-Lowry base.

The formula of the reactant that acts as a proton donor is HCN

The formula of the reactant that acts as a proton acceptor is H2O

Answer:

2.0 V

Explanation:

For the oxidation half cell;

Al(s) -------> Al^3+(aq) + 3e.

For reduction half cell;

Cu^2+(aq) +2e ------> Cu(s).

E°cell = E°cathode - E°anode

But;

E°cathode= 0.34 V

E°anode = -1.66 V

E°cell= 0.34 -(-1.66)

E°cell= 2.0 V

Answer:

They use hypotheses to guess a result based on what they already know. Observations are used to record the results of an experiment. Predictions are used to have an expected outcome of a test, thinking the hypothesis is correct. Experiments are used to test the hypothesis.

Answer:

8.2×10¯⁵ L

Explanation:

82 μL.

We can convert 82 μL to L by doing the following:

To convert from microlitre (μL) to litre(L), we need to know how many microlitre (μL) that makes up a litre (L)

Recall:

1 μL = 1×10¯⁶ L

Therefore,

82 μL = 82 μL × 1×10¯⁶ L/1 μL

82 μL = 8.2×10¯⁵ L

Therefore, 82 μL is equivalent to 8.2×10¯⁵ L

Answer:

Decreasing pH decreases the solubility; increasing salinity increases the salinity.

Explanation:

Atmospheric carbon dioxide in seawater is involved in the following equilibria:

(i)   CO₂(g) ⇌ CO₂(aq)

(ii)  CO₂(aq) + H₂O ⇌ H₂CO₃(aq)  

(iii) H₂CO₃(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HCO₃⁻(aq)  

(iv) HCO₃⁻(aq)+ H₂O(l) ⇌ H₃O⁺(aq) + CO₃²⁻(aq)

1. Effect of pH  

Decreasing pH increases [H₃O⁺].

According to Le Châtelier's Principle, the position of equilibrium of (iv) will be pushed to the left.  

This, in turn, pushes the positions of equilibrium of (iii), (ii), and (i) to the left.

The net effect is that CO₂ is pushed out of the solution and back into the atmosphere.

Thus, decreasing the pH decreases the solubility of atmospheric CO₂.

2. Effect of salinity

Salinity includes the measurement of all ions in seawater, not just Na⁺ and Cl⁻.

An important ion that contributes to salinity is Ca²⁺.

Ca²⁺ ions are involved in the equilibrium  

Ca²⁺(aq) + CO₃²⁻(aq) ⇌ CaCO₃(s).

Thus, increasing the salinity ([Ca²⁺]) removes CO₃²⁻ from the solution and pulls the position of equilibrium of (iv) to the right.

The effect goes back through the chain of equilibria.

The net result is that more atmospheric CO₂(g) dissolves in the seawater to replace the CO₃²⁻ that has been removed.

Increasing the salinity increases the solubility of atmospheric CO₂.

Answer:

- In general, the salt that can make hydrolysis (both ions) is option c (ammonium nitrite).

- Salts that can make hydrolysis (one of the ions) are option a (potassium fluoride), option e (potassium cyanide), option f (sodium benzoate), option h (sodium carbonate) and option k (potassium formiate).

- Surely the neutrals salt are (salts that don't make hydrolysis) option b (sodium nitrate), option d (magnessium sulfate), option g (rubidium iodide) and option i (calcium chloride).

Explanation:

To determine the hydrolysis we have to dissociate the salts, and then we define the conjugate strong bases or acids, that can react to water.

a. KF → K⁺  +  F⁻

F⁻ comes from the HF, a weak acid so the anion is the conjugate strong base. F⁻ can make hydrolysis, but the K⁺, can not.

b. NaNO₃ → Na⁺  +  NO₃⁻

Boths are conjugate weak acid and base, this salt is neutral. So they cannot do hydrolysis.

c. NH₄NO₂  →  NH₄⁺  +  NO₂⁻

Both ions can make hydrolysis to water, because the are conjugate strong base and acid.

The ammonium gives ammonium again:

NH₄⁺  +  H₂O ⇄  NH₃  +  H₃O⁺      Ka

The nitrite gives nitrose acid, again

NO₂⁻ +  H₂O ⇄  HNO₂  +  OH⁻    Kb

d. MgSO₄ → Mg²⁺  +  SO₄⁻²

This is a neutral salt. Boths are conjugate weak acid and base, that's why they can not make hydrolysis.

e. KCN → K⁺  +  CN⁻

As K⁺ comes from a strong base, it can not do hydrolysis.

Then, the cyanide can make hydrolysis because it comes from the HCN (a weak acid), so the ion is the conjugate strong base.

CN⁻  +  H₂O  ⇄  HCN  +  OH⁻

f. C₆H₅COONa  → C₆H₅COO⁻  +  Na⁺

This salt is called sodium benzoate. As Na⁺ comes from a strong base, it can not do hydrolysis. Then, the C₆H₅COO⁻ can make hydrolysis because it comes from the benzoic acid, so the ion is the conjugate strong base.

C₆H₅COO⁻  + H₂O  ⇄  C₆H₅COOH  +  OH⁻         Kb

g. RbI  → Rb⁺  +  I⁻

This is a neutral salt. Similar case as NaCl. Both are conjugate weak acid and base, that's why they can not make hydrolysis.

h. Na₂CO₃ →  2Na⁺  +  CO₃⁻²

The one that can make hydrolysis in this case, is the carbonate anion.

CO₃⁻²  +  H₂O ⇄  HCO₃⁻  +  OH⁻

Carbonate comes from the carbonic acid, a dyprotic weak one.

i. CaCl₂ → Ca²⁺  + 2Cl⁻

This is a neutral salt. Similar case as NaCl. Both are conjugate weak acid and base, that's why they can not make hydrolysis.

j. HCOOK → HCOO⁻  + K⁺

This is the potassium formiate. K⁺ comes from KOH, a strong base. It don't make hydrolysis, while the HCOO⁻ can do the hydrolysis in water.

When the formiate react, we can produce formic acid. Formiate is the conjugate strong base, of a weak acid.

HCOO⁻  + H₂O  ⇄  HCOOH  +  OH⁻

Answer: Well, the volume of the copper is (63.4 - 40.0) * mL = 23.4 * mL

Explanation:

Do you agree? The copper displaces the given volume of water.

Now  ρ Cu =  8.90  ⋅  g  ⋅  c m 3  OR  ρ Cu  =  8.90  ⋅  g  ⋅  m L − 1, i.e.  1 ⋅  m L  ≡  1  ⋅  c m 3

But by definition,  ρ  density  =  mass  volume

And thus  mass  =  ρ  ×  volume  =  8.90  ⋅  g  ⋅  m  L  −  1  ×  23.4  ⋅  m  L

= 208.3 * G

Answer:

four holes

Explanation:

A ball and stick model is a representation of a molecule that can show the number of bonds and sometimes, the stereochemistry of the molecule under study.

The number of holes on present in the ball and stick model for any atom corresponds to the number of bonds that particular atom can form without violating the octet rule.

Carbon is usually tetravalent, it forms four bonds to other atoms. Hence we expect carbon to have four holes.

Answer:

Explanation:

Carbon - Four-hole

Nitrogen - Three-hole

Oxygen - Two-hole

Hydrogyn - Two-hole

Answer:

The correct answer is : 1.07 lbs

Explanation:

solution:

molar mass glucose (C6H12O6) = 180 g/mol

molar mass of oxygen molecule (O2) = 32 g/mol  (as we know molar mass of O = 16 g/mol)

the balanced reaction of conversion of water and oxygen to glucose is:

[tex]C_{6}H_{12}O_{6} + 6O_{2} \rightarrow 6CO_{2} + 6H_{2}O ...(A)[/tex]

1 mol of C6H12O6 = 6 mol of O2  (from reaction A)

so, 180 g C6H12O6 = 192 g O2

that is, 0.396 lb of C6H12O6 = 0.423 lb of O2  (  1 g = 0.00220462 lb )

so,

1 lb C6H12O6 =[tex]\frac{1(lb) \times 0.4233 (lb)}{0.3968 (lb)}[/tex] = 1.07 lb O2

therefore,  the correct answer is : 1.07 lbs

Answer:

Ag+(aq) + Cl-(aq) —> AgCl(s)

Explanation:

2AgNO3(aq) + CaCl2(aq) —>2AgCl(s) + Ca(NO3)2(aq)

The balanced net ionic equation for the reaction above can be obtained as follow:

AgNO3(aq) and CaCl2(aq) will dissociate in solution as follow:

AgNO3(aq) —> Ag+(aq) + NO3-(aq)

CaCl2(aq) —> Ca2+(aq) + 2Cl-(aq)

AgNO3(aq) + CaCl2(aq) –>

2Ag+(aq) + 2NO3-(aq) + Ca2+(aq) + 2Cl-(aq) —> 2AgCl(s) + Ca2+(aq) + 2NO3-(aq)

Cancel out the spectator ions i.e Ca2+(aq) and 2NO3- to obtain the net ionic equation.

2Ag+(aq) + 2Cl-(aq) —> 2AgCl(s)

Divide through by 2

Ag+(aq) + Cl-(aq) —> AgCl(s)

The, the net ionic equation is

Ag+(aq) + Cl-(aq) —> AgCl(s)

Answer:

The percent mass of HCl in the solution is 3.48  %

The percent mass of ethanol in the solution is 6.01  %

The molarity of silver nitrate in the solution is 3.46 M

Explanation:

Density always referrs to solution data.

1.02 g/mL = 100 g / volume of solution

Volume of solution = 98.04 mL

Molarity = moles of solute in 1L of solution (or mmoles of solute in 1mL)

M . 98.04 mL = mmoles of solute → 0.975 M . 98.04 mL = 95.59 mmoles

mmoles . PM (mg / mmol) = mg → 95.59 mmol . 36.45 mg/mmol = 3484 mg.

We convert data to g → 3484 mg . 1g/ 1000 mg = 3.48 g

The percent mass of HCl in the solution is 3.48  %

Density always referrs to solution data.

0.988 g/mL = 100 g / volume of solution

Volume of solution = 101.21 mL

Molarity = moles of solute in 1L of solution (or mmoles of solute in 1mL)

M . 101.21 mL = mmoles of solute → 1.29 M . 101.21 mL = 130.6 mmoles

mmoles . PM (mg / mmol) = mg → 130.6 mmol . 46.07 mg/mmol = 6015 mg.

We convert data to g → 6015 mg . 1g/ 1000 mg = 6.01 g

The percent mass of ethanol in the solution is 6.01  %

Density always referrs to solution data.

1.47 g/mL = 100 g / volume of solution

Volume of solution = 68.03 mL

Molarity = moles of solute in 1L of solution (or mmoles of solute in 1mL)

40 g = 40000 mg

mg / PM (mg / mmol) = mmol → 40000 mg / 169.87 mg/mmol

= 235.4 mmoles

mmoles / mL = Molarity  → 235.4 mmol / 68.03 mL = 3.46 M

Answer:

See explanation

Explanation:

In this case, we can start with the half-reactions. If the total reaction is:

[tex]Zn_(_s_)~+~Cu^2^+~_(_a_q_)~->~Cu_(_s_)~+~Zn^2^+_(_a_q_)[/tex]

If we split the reaction we will have:

Half-reaction 1:

[tex]Zn_(_s_)~->~Zn^2^+_(_a_q_)[/tex]

Half-reaction 2:

[tex]Cu^2^+~_(_a_q_)~->~Cu_(_s_)[/tex]

Now we can add the electrons, keeping in mind that we have to obtain zero charge in both sides of each half-reaction:

Half-reaction 1:

[tex]Zn_(_s_)~->~Zn^2^+_(_a_q_)~+~2e^-[/tex]

Half-reaction 2:

[tex]Cu^2^+~_(_a_q_)~+~2e^-~->~Cu_(_s_)[/tex]

With this in mind, we can solve the questions:

Which one loses electrons?

In half-reaction number 1 we have the electrons in the products side, therefore this half-reaction is the one that loses electrons.

Which one gains electrons

In half-reaction number 2 we have the electrons in the reagent side, therefore this half-reaction is the one that gains electrons.

Which one is oxidized?

If half-reaction number 1 loses electrons will be the oxidation reaction.

Which one is reduced?

If half-reaction number 2 gains electrons will be the reduction reaction.

Which species functions as the oxidizing agent in the following reduction-oxidation reaction?

If half-reaction number 2 is the reduction will be a oxidizing agent.

Which one the reducing agent?

If half-reaction number 1 is the oxidation will be a reducing agent.

I hope it helps!

Answer:

i can't understand the question

Answer:

d. To the left because Q > K_p

Explanation:

Hello,

In this case, for the given reaction:

[tex]CaCO_3(s) \rightarrow CaO(s) + CO_2(g)[/tex]

The pressure-based equilibrium expression is:

[tex]Kp=p_{CO_2}[/tex]

In such a way, since Kp is given we rather compute the reaction quotient at the specificed pressure of carbon dioxide as shown below:

[tex]Q=p_{CO2}=1.0[/tex]

Therefore, since Q>Kp we can see that there are more products than reactants, which means that the reaction must shift leftwards towards the reactants in order to reestablish equilibrium, thus, answer is d. To the left because Q > Kp.

Regards.

Answer:

It shouldn't, but it might there is a chance. Liquid doesn't really weigh that much but it still can add slight weight.

Explanation:

The chemical could maybe make the balancer move a bit. But not a lot.

Answer:

pH of the buffer is 10.10

Explanation:

trimethylamine is a weak base that, in presence with its conjugate base, trimethylammonium ion, produce a buffer.

To determine the pH of the buffer we use H-H equation for weak bases:

pOH = pKb + log [Conjugate acid] / [Weak base]

pKb is -log Kb = 4.20

pOH = 4.20 + log [N(CH₃)₃] / [NH(CH₃)₃]

Replacing the concentrations of the problem:

pOH = 4.20 + log [0.20M] / [0.40M]

pOH = 3.90

As pH = 14 -pOH

Answer:

D.A high temperature will make it spontaneous.

Explanation:

we know that

Δ G = Δ H - TΔS

For spontaneous reaction

Δ G should be negative . If Δ G = 0

Δ H =  TΔS

T =   Δ H / Δ S

At temperature above this T , Δ G becomes negative if Δ S and ΔH are  positive .

So at a  high temperature will make it spontaneous.

Answer:

D. A high temperature will make it spontaneous.

Explanation:

A P E X

Answer:

Chloride (Cl⁻) and sodium (Na⁺) ions.

Explanation:

Hello,

In this case, since the aqueous species are actually dissociated when reacting and the solid species (ferric carbonate) remains undissolved, we can modify the given reaction as follows:

[tex]FeCl_2(aq) + Na_2CO_3(aq) \rightarrow FeCO_3(s) + 2NaCl(aq)[/tex]

In such a way, dissociating the aqueous species we obtain:

[tex]Fe^{2+}(aq)+2Cl^-(aq) + 2Na^+(aq)+CO_3^{2-}(aq) \rightarrow FeCO_3(s) + 2Na^+(aq)+2Cl^-(aq)[/tex]

It means that the net ionic equation is:

[tex]Fe^{2+}(aq)+CO_3^{2-}(aq) \rightarrow FeCO_3(s)[/tex]

Therefore, the spectator ions are those were cancelled out, chloride (Cl⁻) and sodium (Na⁺).

Best regards.

Answer:

The correct answer is "C. Qc > Kc, the reaction proceeds from right to left to reach equilibrium"

Explanation:

The reaction quotient Qc is a measure of the relative amount of products and reactants present in a reaction at a given time.

Being:

aA + bB ⇔ cC + dD

where a, b, c and d are the stoichiometric coefficients of the balanced equation, the coefficient Q is calculated as:

[tex]Qc=\frac{[C]^{c}*[D]^{d} }{[A]^{a} *[B]^{b} }[/tex]

If Qc <Kc there is less concentration of products than in equilibrium, with which the reaction will evolve to the right to increase the concentration of products.  

If Qc> Kc, it is possible to affirm that the reaction will evolve to the left since in this case the direct reaction predominates and there will be more product present than what is obtained in equilibrium. Therefore, this product is used to promote the reverse reaction and achieve equilibrium. Then the system will evolve to the left to increase the concentration of reagents.

If Qc = Kc, it means that the reaction is in equilibrium.

In the case of the reaction:

2 SO₂ (g) + O₂ (g) ⇔ 2 SO₃(g)

the value of the constant Qc is calculated as:

[tex]Qc=\frac{[SO_{3} ]^{2} }{[SO_{2} ]^{2} *[O_{2} ]}[/tex]

Being:

and replacing:

[tex]Qc=\frac{10^{2} }{0.010^{2} *0.010}[/tex]

you get:

Qc=100,000,000=1*10⁸

Being Kc=4.3*10⁶, then Qc>Kc and the reaction proceeds from right to left to reach equilibrium.

So the correct answer is "C. Qc > Kc, the reaction proceeds from right to left to reach equilibrium"