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1. a. 3

b. 2

2. a. 4

b. 6

3. a. 1

b. 2

4. a. 5

Answer: - 1.45 kJ

Explanation:

Using q  = m x C x (ΔT)

Given : m = 3.8 g  , C = 0.900 J/g°C,  = -(450-25)°C = -425°C  (Since final temperature is less than the initial, the sign is negative)

q = (3.8 g) x (0.900 J/goC) x ( -425 °C)

= -1453.5 J

= -1.45 kJ

Note that negative sign of q indicates that this much heat is released, when the metal cools down.

A. The percentage yield of gold chloride is 58%

B. The number of mole of Al produced is 40 moles

2Au + 3Cl₂ → 2AuCl₃

Molar mass of Au = 197 g/mol

Mass of Au from the balanced equation = 2 × 197 = 394 g

Molar mass of Cl₂ = 2 × 35.5 = 71 g/mol

Mass of Cl₂ from the balanced equation = 3 × 71 = 213 g

Molar mass of AuCl₃ = 197 + (3×35.5) = 303.5 g/mol

Mass of AuCl₃ from the balanced equation = 2 × 303.5 = 607 g

We'll begin by determining the limiting reactant

From the balanced equation above,

394 g of Au reacted with 213 g of Cl₂

Therefore,

39.4 g of Au will react with = (39.4 × 213) / 394 = 21.3 g of Cl₂

From the above, both Au and Cl₂ are limiting reactant.

Next, we shall determine the theoretical yield.

From the balanced equation above,

394 g of Au reacted to produce 607 g of AuCl₃

Therefore,

39.4 g of Au will react to produce = (39.4 × 607) / 394 = 60.7 g of AuCl₃

Thus, the theoretical yield of AuCl₃ is 60.7 g

Finally, we shall determine the percentage yield.

Actual yield = 35.2 g

Theoretical yield = 60.7 g

Percentage yield =?

Percentage yield = (Actual / Theoretical) × 100

Percentage yield = (35.2 / 60.7) × 100

Percentage yield = 57.99%

Percentage yield ≈ 58%

Balanced equation

2Al₂O₃ → 4Al + 3O₂

From the balanced equation above,

2 moles of Al₂O₃ produced 4 moles of Al

Therefore,

20 moles of Al₂O₃ will produce = (20 × 4) / 2 = 40 moles of Al

Thus, 40 moles of Al were obtained from the reaction.

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Answer:

OF6

Explanation:

Oxygen and fluorine have almost the same electronegativity, so oxygen isn't able to donate enough electron density to fluorine to form OF6. Atomic size. There isn't enough room around an oxygen atom for six fluorine atoms.

:-befrank

Answer:

i think it is 0.002831392

Explanation:

pOH = 14 - 11.452 = 2.548

pOH = -log(OH)

2.548 = -log(OH)

10^(-2548) = 0.002831392

Answer:

36 grams

Explanation:

Na    22.989

O       15.999

H     1.008          total  39.996   gm per mole

80 grams    is    80 / 39.996 = ~ 2 moles

From the equation each mole of NaOH used results in ONE mole of H2O

   so you will get two moles of H20

       (1.008 *2 + 15.999)   * 2 =  ~ 36 gm

If 162.35 g aluminum hydroxide are dissolved in 6750 mL of solution, the concentration of the solution is 0.308M

The concentration of a solution can be calculated using the following formula:

Molarity = no of moles ÷ volume (L)

However, the number of moles in 162.35g of Al(OH)3 must be calculated as follows:

Molar mass of Al(OH)3 = 78g/mol

no of moles = 162.35g ÷ 78mol

no of moles = 2.08mol

Molarity = 2.08mol ÷ 6.75L

Molarity = 0.308M

Therefore, if 162.35 g aluminum hydroxide are dissolved in 6750 mL of solution, the concentration of the solution is 0.308M.

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Answer:

I would have to say the answer is A) iron. I say this because Iron is one of the most well know conductors and in the chart it as rubber and copper as the two conductors whole Air and Iron should be the x. Plus the rest don't make good conductors they are more insulators. So logicaly it wouldn't make sense to have any of the other answers.

Explanation:

Hope This Helps

Have A Great Day

~Zero~

According to the concept of conduction, iron  belongs in the area marked with an X.

Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold.

In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .

When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:

1) heat conduction

2) electrical conduction

3)sound conduction

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Answer:

4332.5 j

Explanation:

Specific heat of water is 4.186 j /g-C

4.186 j / g-C  * 75 g  * (36.1-22.3 C) =

Answer:

1.837 atm

Explanation:

According to Boyle's Law:

[tex]V_{1} P_{1} = V_{2}P_{2}[/tex]

(22.6L) (3.6atm) = (44.3L) (x)

x = 81.36 /44.3

x = 1.837 atm

This is because Volume and Pressure are inversely proportional. If one increases the other has to decrease.

Answer:

It's C.

Explanation:

According to the site, "http://needtoknow.nas.edu/energy/energy-sources/renewable-sources/wind/" ... "Wind energy is an indirect form of solar energy created by a combination of factors, including the uneven heating of Earth’s atmosphere by solar radiation, variations in topography, and the rotation of Earth. People have been putting wind energy to use throughout history to propel sail boats, mill flour from grain, and pump water."

the question isnt clear where are the products ir the reactants like __ = ___ + ___

Answer:

a reaction that can occur in both forward and reverse directions at the same time.

Explanation:

This is because ↓

A reversible reaction is a reaction in which the conversion of reactants to products and the conversion of products to reactants occur simultaneously. A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B.

Hope this helps =)

Answer:

c

Explanation:

Given that sodium hydroxide is a base, it's pH has to be above pH 7. Thus, option c is the correct option.

On the other hand, acids have a pH of lesser than 7 while pure water has a pH of 7. All the other options have a pH of less than 7, indicating that they are acids.

Answer:

About 2.29 M.

Explanation:

Recall that molarity is defined by moles of solute over liters of solution.

Our solute is 105 grams of calcium nitrate (Ca(NO₃)₂)).

Convert 105 grams of Ca(NO₃)₂ to moles. The molecular weight of Ca(NO₃)₂ is 164.10 g/mol:

[tex]\displaystyle 105\text{ g Ca(NO$_3$)$_2$}\cdot \frac{1\text{ mol Ca(NO$_3$)$_2$}}{164.10\text{ g Ca(NO$_3$)$_2$}} = 0.640\text{ mol Ca(NO$_3$)$_2$}}[/tex]

Convert 280. grams of water to liters. Recall that the density of water is given by 1.00 g/mL:

[tex]\displaystyle \begin{aligned} D & = \frac{m}{V} \\ \\ V & = \frac{m}{D} \\ \\ & = \frac{(280.\text{ g})}{\left(\dfrac{1.00\text{ g}}{1\text{ mL}}\right)} \\ \\ & = 280. \text{ mL}\cdot \frac{1\text{ L}}{1000\text{ mL}} = 0.280\text{ L soln.}\end{aligned}[/tex]

Hence, the molarity of the solution is:
[tex]\displaystyle \begin{aligned} \text{M} &= \frac{\text{ mols solute}}{\text{L soln.}} \\ \\ & = \frac{(0.640\text{ mol})}{(0.280\text{ L soln.})} \\ \\ & = 2.29\text{ M} \end{aligned}[/tex]

In conclusion, the solution is about 2.29 M.

Answer:

its legislative.

Answer:

b. Individual atoms of argon

Explanation:

Hope this helps!

-Justin

Answer:

burrowers

Explanation:

Answer:

3.33 moles

Explanation:

We know that our limiting reactant is chlorine so we just have to figure out how much of the product aluminum chloride (AlCl3) would be formed from 5 moles of chlorine gas. As we can see in the balanced equation, the mole ratio of chlorine gas (Cl2) to aluminum chloride is 3:2 based on the coefficients of the species. All you have to do from here is divide the amount of moles of chlorine gas by its own coefficient and then multiply the number you receive by the coefficient of AlCl3.

5/3=1.66

1.66*2=3.33

Answer:107.868 grams 

Explanation: I’m really sorry if it’s wrong:-(

Answer:

107.8682 grams

Explanation:

The molar mass of a substance is the mass in grams of one mole of that substance. This mass is given by the atomic weight of the chemical unit that makes up that substance in atomic mass units (amu). For example, silver has an atomic weight of 107.8682 amu, so one mole of silver has a mass of 107.8682 grams

The initial temperature of the copper piece if a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C is 345.5°C

The initial temperature of the copper metal can be calculated using the following formula on calorimetry:

Q = mc∆T

mc∆T (water) = - mc∆T (metal)

Where;

According to this question, a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C. If the final temperature of water is 42.0 °C, the initial temperature of the copper is as follows:

400 × 4.18 × (42°C - 24°C) = 240 × 0.39 × (T - 24°C)

30,096 = 93.6T - 2246.4

93.6T = 32342.4

T = 345.5°C

Therefore, the initial temperature of the copper piece if a 240.0 gram piece of copper is dropped into 400.0 grams of water at 24.0 °C is 345.5°C.

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Answer:

the correct answer is 364

q = m * c * ΔT

where q is the heat absorbed or released, m is the mass of the substance, c is the specific heat capacity of the substance, and ΔT is the change in temperature.

We can assume that the heat lost by the copper is gained by the water, so:

q(copper) = -q(water)

where the negative sign indicates that the copper loses heat while the water gains heat.

The specific heat capacity of copper is 0.39 J/g °C, so:

q(copper) = 240.0 g * 0.39 J/g °C * (T(copper) - 24.0 °C)

The specific heat capacity of water is 4.18 J/g °C, so:

q(water) = 400.0 g * 4.18 J/g °C * (42.0 °C - T(copper))

Setting q(copper) equal to -q(water), we get:

240.0 g * 0.39 J/g °C * (T(copper) - 24.0 °C) = -400.0 g * 4.18 J/g °C * (T(copper) - 42.0 °C)

Simplifying and solving for T(copper), we get:

T(copper) = [(400.0 g * 4.18 J/g °C * 42.0 °C) + (240.0 g * 0.39 J/g °C * 24.0 °C)] / (240.0 g * 0.39 J/g °C + 400.0 g * 4.18 J/g °C)

T(copper) = 364.1 °C

Therefore, the initial temperature of the copper piece was 364.1 °C.

Hence, the answer is "364 °C".

Answer:

The answer is C. Inability to sleep properly for weeks.

Explanation:

This means that your mental health is going downhill because the lasck of sleep can drive you insane.

Hope This Helps!

-Justin:)

The gas given off at the cathode is hydrogen while the gas given off at the anode is oxygen.

The term electrolysis has to do with the decomposition of a substance by the passage of direct current through it.

The ions present in the system are H^+, OH^- and NO3^- ions. The gas given off at the cathode is hydrogen while the gas given off at the anode is oxygen.

The half reaction equation of the reduction is;

2H^+(aq) + e ----->H2(g)

The oxidation half reaction equation is;

4OH^- (aq)------> 2H2O(l) + 4e

The overall equation is;

4H^+(aq) + 4OH^- (aq)------> 4H2(g) + 2H2O(l) + 4e

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Answer:

The answer is Edema caused by the pathogen raises the body temperature. :)

Have an amazing day!!!

Please rate and mark brainliest!!

Answer:

Middlesbrough, North Yorkshire

,,Explanation:

Answer:

2.46×10²¹atoms

Explanation:

[tex]molar \: mass \: of \: the \: sucrose = 12(12) + 22(1) + 11(16) \\ = 144 + 22 + 176 \\ = 342g {mol}^{ - 1} \\ mole = \frac{1.4 \times {10}^{ - 3} }{342} \\ = 4.09 \times {10}^{ - 6} \\ number \: of \: atoms = 4.09 \times {10}^{ - 6} \times 6.022 \times {10}^{23} \\ = 2.46 \times {10}^{21} atoms[/tex]

Answer:

the basic elements of environment are lithosphere, hydrosphere, atmosphere and biosphere.

Explanation:

Answer:

.03483 moles

Explanation:

.45 * 77.4/1000 =