3) Report how many significant figures each of the following numbers has and then write the number in
standard scientific notation.
Number
Number of Significant Figures
Standard Scientific Notation
0.0000620
0.05600
70820.0
309100​

Answer:

like, plasmas have no fixed shape or volume, and are less dense then solid or liquids but unlike ordinary gases, plasma are made up of atoms in which some or all of the electrons have been stripped away and positively charged nuclei, called ions, roem freely

Answer:

7.376 × 10^9 people

Explanation:

yes

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:

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:

333.6 atm

Explanation:

The following data were obtained from the question:

Mole of O2 (nO2) = 3.96 moles

Mole of N2 (nN2) = 7.49 moles

Mole of CO2 (nCO2) = 1.19 moles

Total pressure = 563 mmHg

Partial pressure of N2 =..?

Next, we shall determine the total number of mole in the container.

This can be obtained as follow:

Mole of O2 (nO2) = 3.96 moles

Mole of N2 (nN2) = 7.49 moles

Mole of CO2 (nCO2) = 1.19 moles

Total mole =?

Total mole = nO2 + nN2 + nCO2

Total mole = 3.96 + 7.49 + 1.19

Total mole = 12.64 moles

Next, we shall determine the mole fraction of N2.

This can be obtained as follow:

Mole fraction = mole of substance/total mole

Mole of N2 (nN2) = 7.49 moles

Total mole = 12.64 moles

Mole fraction of N2 =?

Mole fraction of N2 = 7.49/12.64

Finally, we shall determine the partial pressure of N2.

This can be obtained as follow:

Mole fraction of N2 = 7.49/12.64

Total pressure = 563 mmHg

Partial pressure of N2 =..?

Partial pressure = mole fraction x total pressure

Partial pressure of N2 = 7.49/12.64 x 563

Partial pressure of N2 = 333.6 atm

The, the partial pressure of nitrogen, N2 is 333.6 atm

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

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:

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:

[See Below]

Explanation:

13 cm.

Answer:

- Not balanced.

- Reactants: Zn  and HCI .

- Products: ZnCl₂ and  H₂.

- Substitution reaction.

Explanation:

Hello,

In this case, for the given reaction:

Zn  +  HCI  →  ZnCl₂ +  H₂

We can see that it is not balanced due to the fact that at the left side we have one hydrogen atom whereas at the right side two, taking into account the number must be same as well as chlorine. Thus, in order to balance we write:

Zn  +  2HCI  →  ZnCl₂ +  H₂

And that is enough. Moreover, we can see that the chemical species at the left side of the equation are the reactants and those at the right side the products, thus we have:

Reactants: Zn  and HCI .

Products: ZnCl₂ and  H₂.

Finally, since we can see that the chlorine is at the reactants with hydrogen, but at the end with the zinc, and the initial zinc is alone as well as the yielded hydrogen we can infer this is a substitution reaction.

Best regards.

Answer:

The equation isn't balanced because there aren't equal numbers of hydrogen or chlorine atoms on both sides of the equation. To correct this, a coefficient of 2 must be placed in front of HCl on the left-hand side of the equation.

Explanation:

Answer:

Explanation:

Diameter in the coin is the distance from side to side.

The numbers in the ruler are showing the centimeters. Each line is a subdivision in ten parts between centimeter and centimeter (Each line is equal to 1mm).

As you can see in the ruler, in the edge of the coin, the ruler is showing 3.8cm

As 1cm = 10mm:

3.8cm * (10mm / 1cm) =

38mm is the diameter of the coin to the nearest milimeter

Answer:

38m

Explanation:

Answer: 89.345

Explanation:

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:

- 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:

See the answer below

Explanation:

From the illustration;

1 chain = 20.1 meters

1 talent = 30.2 kg

The map says the treasure chest was buried 27 chains due west and 3 chains deep under the ground.

27 x 20.1 = 542.7 meters.

3 x 20.1 = 60.3 meters

This means that one would need to travel 542.7 meters due west from the US Capitol and dig 60.3 meters under the ground in order to locate the treasure chest.

The treasure chest has 50 talents of gold:

50 x 30.2 = 1,510 kg of gold.

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:

A practical pursuit of alchemy was the development of metallurgy practices.

Explanation:

As alchemists always tried to turn various metals into other things, metalworking techniques were developed even though their experiments were often unsuccessful.

Answer: developing metalworking techniques

Explanation:

trust it!!

Answer: When silver is exposed to sulfur-containing gases in the air, it discolours and then darkens as it reacts with the gas to form a surface layer of tarnish. This process is called tarnishing.

Hope this helped :)

Answer:

a) Insoluble

b) Soluble

c) Insoluble

d) Insoluble

e) Soluble

f) Soluble

Explanation:

Answer:

a number should be rounded up it is 5 or higher

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:

Percent yield = 70.8%

Explanation:

Equation of the reaction:

Al2O3 + 3C ----> 2Al + 3CO

From the reaction equation, 1 mole of Aluminum oxide produces 2 moles of Aluminum when reacted with 3 moles of carbon.

Molar mass of Aluminum oxide = 102 g; molar mass of Aluminum = 27 g; molar mass of C = 12

3 moles of C = 36 g

2 moles Al = 54 g

102 g of Al2O3 reacts with 36 g of C

60 g of Al2O3 will react with (36/102) × 60 g of C = 21.2 g of C

Therefore, Al2O3 is the limiting reactant while C is in excess.

102 g of Al2O3 produces 54 g of Al

60 g of Al2O3 will produce (54/102) × 60 of Al = 31.8 g of Al

Percent yield = (actual yield/ theoretical yield) × 100%

Percent yield = (22.5 g / 31.8 g) × 100%

Percent yield = 70.8 %

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:

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:

pH after the addition of NaOH is 4.37

Explanation:

When the amount of the weak acid = Amount of the conjugate base (As in the problem) pH = pKa. That means pKa of benzoic buffer is 4.19.

Now, to solve the pH of the buffer we need to use H-H equation for benzoic buffer:

pH = pKa + log [Benzoate] / [Benzoic acid]

pH = 4.19+ log [Benzoate] / [Benzoic acid]

You can take [] concentrations as the moles of both species.

When you add NaOH to the buffer, it reacts with benzoic acid producing more sodium benzoate and water, thus:

NaOH + Benzoic Acid → Sodium benzoate + Water.

Before the reaction, moles of benzoic acid and sodium benzoate were:

500.0mL = 0.500L × (0.10mol / L) = 0.050 moles

After the reaction, 0.010 moles of Benzoic acid are consumed and the same 0.010 moles of sodium benzoate are produced. That means moles of both species after reaction are:

[Benzoate] = 0.050 moles + 0.010 moles = 0.060 moles

[Benzoic acid] = 0.050 moles - 0.010 moles = 0.040 moles

Replacing in H-H equation:

pH = 4.19+ log [Benzoate] / [Benzoic acid]

pH = 4.19+ log [0.060mol] / [0.040mol]

pH = 4.37

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.

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:

Al

Explanation:

4 Al  +  3 O₂  →  2 Al₂O₃

You need to figure out which one has the smaller mole ratio.  Convert both substances from grams to moles.

(10.0 g Al)/(26.98 g/mol) = 0.3706 mol Al

(19.0 g O₂)/(32.00 g/mol) = 0.5938 mol O₂

Now, use the mole ratios of reactant to product to see which substance produces the least amount of product.

(0.3706 mol Al) × (2 mol Al₂O₃/4 mol Al) = 0.1853 mol Al₂O₃

(0.5938 mol O₂) × (2 mol Al₂O₃/3 mol O₂) = 0.3958 mol Al₂O₃

Since aluminum produces the least amount of product, this is the limiting reagent.

Al is a limiting reagent. A further explanation is below.

Given equation,

So,

4 moles of Al reacts with 3 moles of O₂ to produce 2 moles of Al₂O₃.

then,

Number of moles of Al,

= [tex]\frac{10 \ g}{26.98 \ g/mol}[/tex]

= [tex]3.706\times 10^{-1} \ moles[/tex]

Now,

then,

Number of moles of O₂,

= [tex]\frac{19 \ g}{32 \ g/mol}[/tex]

= [tex]5.937\times 10^{-1} \ moles[/tex]

Now,

[tex]5.937\times 10^{-1} \ moles[/tex] of O₂ can react with,

= [tex]4\times \frac{5.937\times 10^{-1}}{3}[/tex]

= [tex]7.916\times 10^{-1} \ moles \ of \ Al[/tex]

But there is only [tex]3.706\times 10^{-1}[/tex] moles of Al available.

Thus the above approach is right.

Learn more:

https://brainly.com/question/1983373

Answer:

The Lewis structure for CO2 is O = C = O rather than  O ≡ C - O because of the covalent nature of the bonds that makes CO2 a polar molecule and to become stable it is important to fill valence shell of both atoms equally.

CO2 can not be written as O ≡ C - O because then there will be one non-paired electron in the oxygen atom that can disturb the stability of CO2.