For the reaction CH4 + 2O2 = 2H2O + CO2
How many moles of water are produced from the combustion of 45.2 grams od methane (CH4)? Please show all work.

Answer:

w = 7376.6 J

Explanation:

To calculate the work done in the system, we need first to calculate the number of moles of all compounds.

The following expression, that comes from the 1° law of thermodynamic, will help you to get the work:

w = ΔnRT

Where:

Δn: difference in the number of moles between products and reactants

R: constant universal of gases (8.314 J / mol K)

T: Temperature in Kelvin.

As we are doing this reaction in STP, then the Pressure is 1 atm, and temperature is 0 °C or 273 K.

Now, we already have the moles of Cu₂O, let's see, according to the balanced reaction, how many moles we should have of O₂ and CuO.

If 1 mole of O₂ reacts with 2 moles of Cu₂O then 6.5 moles of Cu₂O will be:

moles O₂ = 6.5 moles Cu₂O * (1 mole O₂/2 moles Cu₂O) = 3.25 moles O₂

If 2 moles of Cu₂O produces 4 moles of CuO, then 6.5 moles will be:

moles CuO = 6.5 moles Cu₂O*(4 moles CuO/2 moles Cu₂O) = 13 moles CuO

Now that we have the moles, let's calculate the value of Δn.

Δn = moles product - moles reactants

Δn = 13 - (6.5 + 3.25) = 3.25 moles

Now, we can calculate the work done in the system:

w = 3.25 * (8.314 * 273)

Hope this helps

Explanation:

We can summarize the reaction shown as:

                2F₂  +   I₂  →   2F₃I

Since I is purple

         F is the green

The number of I atoms in the reactants is greater than the number in the product

False:

The number of I atoms on both side of the expression is 2

There are 4 atoms of F in both the reactants and the products.

False:

There are 4 atoms of F on the reactant side and 6 atoms of F on the product side

The illustration represents a valid chemical transformation. True or false

False

The reaction does not represent a valid chemical transformation because in a valid chemical transformation, the number of atoms on both sides of the expression must be the same.

Answer:

The correct answer is - 15.625

Explanation:

The half-life is the time it takes to decay half value or quantity of its initial quantity or value. It is given that,

The half-life of K-42 = 12.4 hours

The initial value of K-42 = 500 gm

After 62 hours the value of k-42 = ?

The number of half cycle = 62*1/12.4 = 5,

therefore it will have 5 half-lives

initial - 500

1st half life - 500/2 = 250

2nd - half life - 250/2 = 125

3rd half life - 125/2 = 62.5

4th half life - 62/2 = 31.25

fifth half life - 31.25/2 = 15.625

Thus, the correct answer is =15.625g

15.625 g of  a 500 gram sample of potassium-42 with 12.4 hours of Half -life is left after 62 hours.

The half-life is the time after which half of the initial quantity of a radioactive substance is left .

Given here,  

The half-life of K-42 = 12.4 hours  

The initial quantity of K-42 = 500 gm  

The final quantity after 62 hours = ?  

The number of half cycle

[tex]\bold { = 62\times \dfrac 1{12.4} = 5,}[/tex]  

Thus the number of half life cycles in 62 hours is 5,

After 1 half life [tex]\bold {= \dfrac {500}{2} = 250}[/tex]  

After 2 half lives [tex]\bold {= \dfrac {250}{2} = 125}[/tex]  

After 3 half lives [tex]\bold {= \dfrac {125}{2} = 62.5}[/tex]  

After 4 half lives  [tex]\bold {= \dfrac {62.5}{2} = 31.25}\\[/tex]  

After 5 half lives [tex]\bold {= \dfrac {31.25}{2} = 12.625}\\[/tex]  

15.625 g of  a 500 gram sample of potassium-42 with 12.4 hours of Half -life is left after 62 hours.

To know more about Half life,

https://brainly.com/question/4483570

Answer:

[tex]C_7H_8N_4O_2[/tex]

Explanation:

Hello!

In this case, since the determination of an empirical formula is covered by first computing the moles of each atom as shown below:

[tex]n_C=\frac{46.47g}{12g/mol}=3.9mol\\\\ n_H=\frac{4.48g}{1g/mol} =4.5mol\\\\n_N=\frac{31.10g}{14g/mol} =2.2mol\\\\n_O=\frac{17.76g}{16g/mol} =1.1mol[/tex]

Now, we divide each moles by the fewest moles (those of oxygen), to obtain the subscripts in the empirical formula:

[tex]C:\frac{3.9}{1.1}=3.5 \\\\H:\frac{4.5}{1.1}=4 \\\\N:\frac{2.2}{1.1} =2\\\\O:\frac{1.1}{1.1} =1[/tex]

Thus, the empirical formula, taken to the nearest whole subscript is:

[tex]C_7H_8N_4O_2[/tex]

Whose molar mass is 180.16, therefore the empirical formula is the same to the molecular one.

Best regards!

Explanation:

Can you edit your question and get a better pic because I cant see anything. Its blurry.

Answer:

1.42 moles

Explanation:

25.58 g of H₂O .

Molecular weight of water = 2 x 1 + 16 = 18

1 mole of water = 18 g of water

18 g of water = 1 mole

25.58 g of water = 25.58 / 18 mole

= 1.42 moles .

Answer:

D =  42.6 g

Explanation:

Given data:

Mass of oxygen needed = ?

Mass of phosphorus react = 33 g

Solution:

Chemical equation:

4P + 5O₂     →      2P₂O₅

Number of moles of phosphorus:

Number of moles = mass/molar mass

Number of moles = 33 g/ 30.97 g/mol

Number of moles = 1.065 mol

now we will compare the moles of P and oxygen.

                P         :       O₂

                4         :        5

          1.065        :        5/4×1.065 = 1.33mol

Mass of oxygen needed:

Mass = number of moles × molar mass

Mass = 1.33 mol × 32 g/mol

Mass = 42.6 g

Answer:

1.  the absolute pressure in the tank before filling = 217 kPa

2. the absolute pressure in the tank after filling = 312 kPa

3. the ratio of the mass after filling M2 to that before filling M1 = 1.44

The correct relation is option c ([tex]\frac{M_{2} }{M_{1} } = \frac{P_{2} T_{1} }{P_{1} T_{2} }[/tex])

Explanation:

To find  -

1. What is the absolute pressure in the tank before filling?

2. What is the absolute pressure in the tank after filling?

3. What is the ratio of the mass after filling M2 to that before filling M1 for this situation?

As we know that ,

Absolute pressure = Atmospheric pressure + Gage pressure

So,

Before filling the tank :

Given - Atmospheric pressure = 100 kPa ,  Gage pressure = 117 kPa

⇒Absolute pressure ( p1 )  = 100 + 117 = 217 kPa

Now,

After filling the tank :

Given - Atmospheric pressure = 100 kPa ,  Gage pressure = 212 kPa

⇒Absolute pressure (p2)  = 100 + 212= 312 kPa

Now,

As given, volume is the same before and after filling,

i.e. [tex]V_{1}[/tex] = [tex]V_{2}[/tex]

As we know that, P ∝ M

⇒ [tex]\frac{p_{1} }{p_{2} } = \frac{m_{1} }{m_{2} }[/tex]

⇒[tex]\frac{m_{2} }{m_{1} } = \frac{p_{2} }{p_{1} }[/tex]

⇒[tex]\frac{m_{2} }{m_{1} } = \frac{312 }{217 } = 1.4378[/tex] ≈ 1.44

Now, as we know that PV = nRT

As V is constant

⇒ P ∝ MT

⇒[tex]\frac{P}{T}[/tex] ∝ M

⇒[tex]\frac{M_{2} }{M_{1} } = \frac{P_{2} T_{1} }{P_{1} T_{2} }[/tex]

So, The correct relation is c option.

The final temperature of the system : 31.5 °C

Given

55.5 g Al, 95 C

500 g water, 30 C

C Al = 0.900 J/gºC

Required

the final temperature

Solution

Q in = Q out

Q absorbed = Q released

Q water = Q Aluminium

[tex]\tt 500\times 4.186\times (t-30)=55.5\times 0.9\times (95-t)\\\\2093t-62790=4702.5-49.5t\\\\2142.5t=67492.5\rightarrow t=31.5^oC[/tex]

Answer: 4.76 * 10^2

476.

you bring the ending decimal to the first number and it takes you two hops to get the first number so that's what you put in the box after the 10

Answer:

a) r = k × [A] × [B]²

b) 3

Explanation:

Let's consider the following generic reaction

A + B + C ⇒ Products

The generic rate law is:

r = k × [A]ᵃ × [B]ᵇ × [C]ⁿ

where

This reaction is first order in A, second order in B, and zero order in C. The rate law is:

r = k × [A]¹ × [B]² × [C]⁰

r = k × [A] × [B]²

The overall order of the reaction is the sum of the individual reaction orders.

1 + 2 + 0 = 3

Answer:

material of the block, the shape of the block and the color of the light

Explanation:

Answer:

11

Explanation:

electronic configuration = 1s^2, 2s^2, 2p^6, 3s^1

therefore total electrons = 2+2+6+1 = 11

Hope it helps youu ｡◕‿◕｡

Answer:

Explanation:

Percent composition of sodium chloride .

NaCl

Mol weight = 23 + 35.5 = 58.5 g

58.5 g of NaCl contains 23 g of Na

100 g of NaCl contains 23 x 100 / 58.5 g of Na

= 39.3 %

Na = 39.3 %

58.5 g of NaCl contains 35.5  g of Cl

100 g of NaCl contains 35.5 x 100 / 58.5 g of Na

= 60.7 %

Cl = 60.7 % .

Answer:

Thermal energy refers to the energy contained within a system that is responsible for its temperature. Heat is the flow of thermal energy. A whole branch of physics, thermodynamics, deals with how heat is transferred between different systems and how work is done in the process (see the 1ˢᵗ law of thermodynamics).

Explanation:

Explanation:

Thermal Energy refers to the energy within a system that is responsible for it temperature etc.

63 g H₂O

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

3.5 mol H₂O

Step 2: Identify Conversions

Molar Mass of H - 1.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

63.07 g H₂O ≈ 63 g H₂O

Answer:

281s

Explanation:

Given parameters:

Speed of the scooter  = 1.45min per mile

Fuel economy of engine  = 85miles per gallon

Quantity of fuel  = 145mL

Unknown:

Time of travel with the volume of fuel given  = ?

Solution:

To solve this problem, we need to find the distance the fuel will last.

 Rate of fuel consumption by the engine  = 85miles per gallon

Convert 145mL to gallons;

                3785.41mL  = 1 gallon

               145mL will therefore give [tex]\frac{145}{3785.41}[/tex]    = 0.038gallons

So;

   Distance covered  = 85miles per gallon  x 0.038gallons  = 3.23miles

From;

             Rate of travel  = [tex]\frac{time }{distance}[/tex]  

       Time  = rate of travel x distance  = 1.45 minutes per mile x  3.23miles

     Time  = 4.7min

             1 min  = 60s

            4.7min  = 4.7 x 60 = 281s

Answer:

Oceanic lithosphere forms at midocean ridges, where hot magma upwells, and then cools to form plates as the material moves away from the spreading center. As the plate cools, heat flow decreases and the seafloor deepens

Explanation:

Brainliest plzzzzzzz

Answer:neutral

Explanation:ionic compounds is between a cation and anion so they cancel eachother out

Answer:

4.6g

Explanation:

We are given the following parameters:

Molecular weight of the compound  = 74g/mol

Volume  = 2500mL  = 2.5L or 2.5dm³

Concentration  = 0.025M

Unknown:

Mass of compound  = ?

Solution:

To solve this problem, we need to find the number of moles from the given concentration and volume values.

     Number of moles  = concentration x volume

So;

      Number of moles  = 0.025 x 2.5  = 0.0625mol

Therefore, mass of compound;

    Mass = number of moles  x molar mass

  Mass  = 0.0625 x 74  = 4.6g

Answer:

This is a chemical change because new substances are formed with different properties and identities.

Answer:

29 L.

Explanation:

Hello!

In this case, considering that we are performing a conversion by which the time should be cancelled out to obtain liters, we first need to convert the seconds on bottom to hours and then the volume on top to liters, just a shown down below:

[tex]2.0\frac{mL}{s} *\frac{1L}{1000mL} *\frac{3600s}{1hr}*4.0hr\\\\=28.8L[/tex]

Which turns out 29 L with 2 significant figures.

Best regards!

The theoretical yield of NaCl : 15 mol

Given

15 mol Na

15 mol Cl₂

Required

The theoretical yield of NaCl

Solution

Reaction

2Na + Cl₂ ⇒ 2NaCl

A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients

Find limiting reactant (mol : coefficient) :

Na = 15 : 2 = 7.5

Cl₂ = 15 : 1 = 15

The limiting reactant = Na(smaller ratio)

Mol of NaCl based on mol Na as limiting reactant.

From the equation, mol ratio of Na : NaCl = 2 : 2, so mol NaCl = 15 mol

Answer:

joe mama

Explanation:

400 + 20 + 420

Explanation:

1inch = 2.54cm

1inch^3= 2.54³ = 16.38cm^3

13.4cm^3 = 13.4*16.38 = 219.5867 cm^3

1lb = 454g

5.14lb = 5.14*454g/lb = 2,333.6g

density g/cm^3 = 2,333.6/219.6cm^3

density = 10.6265938 g/cm^3

to three significant figures:

density = 10.6g/cm^3

Answer:

Copper is more reactive and higher in the activity series

Explanation:

Copper is able to replace the silver in a replacement reaction because it is more reactive and higher in the activity series.

Substances or ions that are higher in the activity series are typically more reactive than those ones below them.

In like manner, they are able to replace the lowers ones in a chemical reaction due to their higher reactivity potential.

A less reactive element and a lower one in the activity series cannot displace a higher one in the series.