I need help with this!!!

Answer:

6059.63 kcal/kg.

Explanation:

CH4 consist of Hydrogen and carbon. Therefore, Hydrogen in CH4 = 12 × 4 = 48 kg,  carbon in CH4 = 12 × 12 = 144kg.

For ethane, the amount of hydrogen present = 2 × 6 = 12kg and that of carbon in ethane = 2 × 24 = 48kg.

The weight of carbon in CO = 15 × 12 = 18kg and the weight of Hydrogen in CO = 15 × 16 = 240kg.

For hydrogen, its weight in H2 = 50 × 2 = 100kg.

For CO2, carbon has = 4 × 12 = 48 kg and oxygen has = 4 × 32 = 128kg.

For C6H6, carbon has 2 × 72 = 144kg and hydrogen has 2 × 6 = 12kg.

For N2, the amount of nitrogen= 11 × 28 = 308 kg.

For CH2= CH2, carbon has 4 × 24 = 96kg and hydrogen = 4 × 4 = 16kg.

The gross calofiric value = 1/100 [ 8080 C + 34500 + ( H - O/8) + 22405].

Where the total weight = 128 + 180+ 48 + 240 + 100 + 144 + 48 + 12 + 48 + 16 + 96 + 308 + 12 + 144 = 1524 kg.

The percentage by weight of carbon = total weight of carbon/total weight × 100.

The total Weight of carbon= 48 + 180 + 144 + 48 +144 + 96 = 660kg.

The percentage weight of carbon = 660/1524 × 100 = 43.3 %.

The percentage weight of hydrogen = total weight of hydrogen/total weight × 100.

The total weight of hydrogen = 100 + 12 + 48 + 16 +12 = 188.

The percentage weight of Hydrogen = 188/ 1524 × 100 = 12.33%.

Percentage weight of oxygen = total weight of oxygen/total weight × 100.

Percentage weight of oxygen = ( 128 + 240) / 1524 × 100 = 24.15%.

The gross calorific value = 1/100 [ 8080 × 43.3 ,+ 34500 ( 13.33 - 24.15/8) ] = 6711.02 kcal/kg.

Net calorific value = 6711.02 - 0.09 × 12.3 × 587 = 6059.63kcal/kg.

Answer:

The pH of the buffer is 3.90

Explanation:

The mixture of a weak acid CH3COOH and its conjugate base CH3COO produce a buffer that follows the equation:

pH = pKa + log [A-] / [HA]

Where pH is the pH of the buffer, pKa is the pKa of acetic acid (4.75), and [A-] could be taken as the moles of the conjugate base and [HA] the moles of thw weak acid.

To solve this question we need to find the moles of the CH3COOH and CH3COO- after the reaction with HCl:

CH3COO- + HCl → CH3COOH + Cl-

The moles of CH3COO- are its initial moles - the moles of HCl added

And moles of CH3COOH are its initial moles + moles HCl added

Moles CH3COO-:

Initial moles  = 0.100L * (0.010mol / L) = 0.00100moles

Moles HCl = 0.010L * (0.050mol / L) = 0.000500 moles

Moles CH3COO- = 0.000500 moles

Moles CH3COOH:

Initial moles  = 0.100L * (0.040mol / L) = 0.00400moles

Moles HCl = 0.010L * (0.050mol / L) = 0.000500 moles

Moles CH3COO- = 0.003500 moles

pH is:

pH = 4.75 + log [0.000500] / [0.00350]

pH = 3.90

The pH of the buffer after addition of 10.0 mL of 50.0mM HCl is 3.90

The Henderson-Hasselbach equation is given as:

where

The formula for calculating number of moles is:

The equation of the reaction is given below:

CH3COO- + HCl → CH3COOH + Cl-

moles of CH3COO- = initial moles - moles of HCl added

moles of CH3COOH = initial moles + moles HCl added

Moles CH3COO-

Molarity = 0.010 M

volume = 100 mL = 0.100 L

Initial moles  = 0.100 L * 0.010 M = 0.001 moles

Moles HCl = 0.010L * 0.050 M= 0.0005 moles

Moles CH3COO- = 0.001 - 0.0005 moles

Moles of CH3COO- = 0.000500 moles

Moles CH3COOH:

Molarity = 0.040 M

volume = 100 mL = 0.100 L

Initial moles  = 0.100L * (0.040mol / L) = 0.00400moles

Moles HCl = 0.010L * (0.050mol / L) = 0.000500 moles

Moles CH3COO- = 0.004 - 0.0005 moles

Moles CH3COO- = 0.003500 moles

Substituting the calculated values:

pH = 4.75 + log [0.000500] / [0.00350]

pH = 3.90

Therefore, the pH of the buffer after addition of the 10.0 mL 50.0mmHg HCL is 3.90

Learn more about about buffers and pH at: https://brainly.com/question/11851669

Answer:

1. 0.097 s

2. 0.420 M

Explanation:

To solve both questions we'll use the formula:

[A]ₓ = [A]₀ - kt

Where [A]ₓ is the concentration of A at a given time; and [A]₀ is the initial concentration.

1) We input the data given by the problem:

0.167 M = 0.700 M - 5.48 M/s * t

And solve for t:

t = 0.097 s

2) We input the new data:

[A]ₓ = 0.500 M - 0.361 M/s * 0.220 s

and solve for [A]ₓ:

[A]ₓ = 0.420 M

Answer:

6.78 × 10⁻³ L

Explanation:

Step 1: Write the balanced equation

Mg₃N₂(s) + 3 H₂O(g) ⇒ 3 MgO(s) + 2 NH₃(g)

Step 2: Calculate the moles corresponding to 10.2 mL (0.0102 L) of H₂O(g)

At STP, 1 mole of H₂O(g) has a volume of 22.4 L.

0.0102 L × 1 mol/22.4 L = 4.55 × 10⁻⁴ mol

Step 3: Calculate the moles of NH₃(g) formed from 4.55 × 10⁻⁴ moles of H₂O(g)

The molar ratio of H₂O to NH₃ is 3:2. The moles of NH₃ produced are 2/3 × 4.55 × 10⁻⁴ mol = 3.03 × 10⁻⁴ mol.

Step 4: Calculate the volume corresponding to 3.03 × 10⁻⁴ moles of NH₃

At STP, 1 mole of NH₃(g) has a volume of 22.4 L.

3.03 × 10⁻⁴ mol × 22.4 L/mol = 6.78 × 10⁻³ L

Answer:  The mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol is 0.93

Explanation:

Given : Volume of ethanol (solvent) = 21.10 ml

density of ethanol (solvent)= 0.789 g/ml

Mass of ethanol (solvent) = [tex]0.789g/ml\times 21.10ml=16.6g[/tex]

Mass of glycerol (solute) = 2.51 g

Mole fraction of a component is the ratio of moles of that component to the total moles present.

moles of ethanol =[tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{16.6g}{46g/mol}=0.36mol[/tex]

moles of glycerol =[tex]\frac{\text {given mass}}{\text {molar mass}}=\frac{2.51g}{92g/mol}=0.027mol[/tex]

mole fraction of ethanol (solvent) = [tex]\frac{\text {moles of ethanol}}{\text {moles of ethanol + moles of glycerol}}=\frac{0.36}{0.36+0.027}=0.93[/tex]

The mole fraction of the solvent in a solution that contains 2.51 g glycerol dissolved in 21.10 mL ethanol is 0.93

Answer:

MgCO₃

Explanation:

From the question given above, we obtained:

MgF₂ + Li₂CO₃ —> __ + 2LiF

The missing part of the equation can be obtained by writing the ionic equation for the reaction between MgF₂ and Li₂CO₃. This is illustrated below:

MgF₂ (aq) —> Mg²⁺ + 2F¯

Li₂CO₃ (aq) —> 2Li⁺ + CO₃²¯

MgF₂ + Li₂CO₃ —>

Mg²⁺ + 2F¯ + 2Li⁺ + CO₃²¯ —> Mg²⁺CO₃²¯ + 2Li⁺F¯

MgF₂ + Li₂CO₃ —> MgCO₃ + 2LiF

Now, we share compare the above equation with the one given in the question above to obtain the missing part. This is illustrated below:

MgF₂ + Li₂CO₃ —> __ + 2LiF

MgF₂ + Li₂CO₃ —> MgCO₃ + 2LiF

Therefore, the missing part of the equation is MgCO₃

Answer:

[H2]2[S2][H2S]2Kc=[H2]2[S2][H2S]2

Explanation:

2H2S(g)⇋2H2(g)+S2(g)2H2S(g)⇋2H2(g)+S2(g)

The equilibrium constant expression in terms of concentrations is:

Kc=[H2]2[S2][H2S]2Kc=[H2]2[S2][H2S]2.

The equilibrium expression for the given reaction can be written in terms of equilibrium constant which is the ratio of power of molar concentration of the product to the product of power of molar concentration of the reactants.

Equilibrium is a state for a reversible reaction where, the rate of forward reaction is equal to the rate of backward reaction. The rate of a reaction is the rate of decrease in the concentration of reactants or the rate of increase in the concentration of the products.

The given reaction at equilibrium state is written as:

[tex]\rm 2H_{2}S (g)\leftrightharpoons 2H_{2} (g)+ S_{2}(g)[/tex]

The equilibrium constant Kb is ratio of power of molar concentration of the product to the product of power of molar concentration of the reactants.

[tex]Kb = \rm \frac{[H_{2}S]^{2}}{[H_{2}]^{2} [S_{2}]}[/tex]

The rate of the reaction will be r = Kb [H₂]² [S₂].

To find more on equilibrium constant, refer here:

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Answer:

Calcium Hydroxide is an ionic compound

Answer:

173.9 mL of HBr

Explanation:

We'll begin by calculating the number of mole in 6.73 g of CaCO₃. This can be obtained as follow:

Mass of CaCO₃ = 6.73 g

Molar mass of CaCO₃ = 40 + 12 + (16×3)

= 40 + 12 + 48

= 100 g/mol

Mole of CaCO₃ =?

Mole = mass / Molar mass

Mole of CaCO₃ = 6.73 / 100

Mole of CaCO₃ = 0.0673 mole

Next, we shall determine the number of mole of HBr that will react with 6.73 g (i.e 0.0673 mole) of CaCO₃. This can be obtained as follow:

2HBr + CaCO₃ —> CaBr₂ + H₂O + CO₂

From the balanced equation above,

2 moles of HBr reacted with 1 mole of CaCO₃.

Therefore, Xmol of HBr will react with 0.0673 mole of CaCO₃ i.e

Xmol of HBr = 2 × 0.0673

Xmol of HBr = 0.1346 mole

Thus, 0.1346 mole of HBr reacted.

Next, we shall determine the volume of HBr needed for the reaction. This can be obtained as follow:

Mole of HBr = 0.1346 mole

Molarity of HBr = 0.774 M

Volume =?

Molarity = mole / Volume

0.774 = 0.1346 / volume

Cross multiply

0.774 × volume = 0.1346

Divide both side by 0.774

Volume = 0.1346 / 0.774

Volume = 0.1739 L

Finally, we shall convert 0.1739 L to mL. This can be obtained as follow:

1 L = 1000 mL

Therefore,

0.1739 L = 0.1739 L × 1000 mL / 1 L

0.1739 L = 173.9 mL

Thus, 173.9 mL of HBr is needed for the reaction.

Answer:

A). Calcium chloride dihydrate (CaCl2 * 2H2O) slowly heated in a crucible to become calcium chloride (anhydrous).

Dehyration is a physical process

B). A hydrocarbon such as propane (C3H8) undergoes combustion to power a grill

Combustion is a chemical process.

C). A rock climber’s rope becomes frayed and turns the color of the rocks

This is physical process

D). A dog urinates on an air conditioner coil and the coil becomes corroded

Corrsion is a chemical process.

Explanation:

The chemical process is combustion and corrosion i.e. B and D. The physical change has been the heating of calcium chloride, and fraying of rock i.e. A and C.

A chemical process has been given as the reaction in which the composition of the sample changes. It has been an irreversible process.

A physical process has been described as a change in the physical properties of substances. It is a reversible process.

The following reaction can be given as:

A. The reaction between calcium chloride and water has been mediated by heating. It is a reversible process and does not change the chemical composition. It is a physical process.

B. The combustion results in the change in the chemical constituents of propane. It is a chemical process.

C. There has been no change in the chemical composition of materials. It has been a physical process.

D. The corrosion has resulted from the chemical change in the iron. It has been a chemical process

Thus, the chemical process is combustion and corrosion. The physical change has been the heating of calcium chloride, and fraying of rock.

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0.836 mol Al

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Stoichiometry

Step 1: Define

[RxN - Balanced] 2Al (s) + 3H₂SO₄ (aq) → Al₂(SO₄)₃ (aq) + 3H₂ (g)

[Given] 0.418 mol Al₂(SO₄)₃

[Solve] x mol Al

Step 2: Identify Conversions

[RxN] 2 mol Al (s) → 1 mol Al₂(SO₄)₃ (aq)

Step 3: Stoich

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

Since our final answer already has 3 sig figs, there is no need to round.

Answer:

Mg donates two electrons to O

Explanation:

Lewis dot notation uses dots and crosses to represent valence electrons on atoms.

Magnesium is a metal and would donate or lose electrons during bonding.

Oxygen is a non metal and would gain electrons during bonding.

The correct option is;

Mg donates two electrons to O

Answer:

The Importance of D-Day

The D-Day invasion is significant in history for the role it played in World War II. It marked the turn of the tide for the control maintained by Nazi Germany; less than a year after the invasion, the Allies formally accepted Nazi Germany's surrender.

Answer:

bulb or pump, meniscus, outside

Explanation:

In order to use a pipet, place a BULB OR PUMP at the top of the pipet. Use this object to fill the pipet such that the MENISCUS of the liquid is even with the volume line. Release the liquid, touching the tip of the pipet to the side of the container if necessary to release the last drop OUTSIDE the pipet tip.

Answer:B) The Skin and The Skin cells

Explanation:

Hope this helped

Answer:

See explanation

Explanation:

The balanced reaction equation of the reaction between SiO2 and HF is shown below;

SiO2(s) + 4HF(aq) = SiF4(g) + 2H2O(l)

b)

2NaF(aq) + CaCl2(aq) --------> 2NaCl(aq) + CaF2(s)

The complete ionic equation is;

2 Na^+(aq) + 2F^-(aq) + Ca^+(aq) + 2 Cl^-(aq)------> 2 Na^+(aq) + 2 Cl^-(aq) + CaF2(s)

The net ionic equation;

Ca^+(aq) + 2F^-(aq) -------> CaF2(s)

Answer:

0.81 moles H2

Explanation:

The equation of the reaction is;

Mg(s) + 2HCl(aq) ------>MgCl2(aq) + H2(g)

Number of moles of HCl reacted = concentration * volume

Number of moles of HCl reacted = 6.44 * 250/1000

Number of moles of HCl reacted = 1.61 moles of HCl

If 2 moles of HCl produces 1 mole of H2

1.61 moles of HCl produces 1.61 * 1/2 = 0.81 moles H2

Answer:

It is D !!

Explanation:

Just did test

Answer:

lol

Explanation:

lol

Answer:

323.22 ml

Explanation:

Given that :

Diameter, d = 6.8cm

Height, h = 8.9cm

V = arh

Recall :

Volume, V = πr²h

Radius, r = diameter / 2 = 6.8 / 2 = 3.4cm

V = π * 3.4^2 * 8.9

V = 323.21961 cm³

Recall:

1ml = 1cm³

Hence,

323.21961 cm³ = 323.21961 ml

Volume = 323.22 ml

Answer:

Explanation

I am sorry but please give detailed question

Answer:

Yes

Explanation:

Answer:

D all the above

Explanation:

Answer:

Answer:- Lions..

Explanation:

Hope you have got your answer..

Happy Learning!..

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Answer:

Independent

Explanation:

Independent Variable is the volume of the object. Dependent Variable is the mass of the object. So it