(5x10^3) + (4.3x10^4)=

Answer:

The answer is 7.89

Explanation:

Mass of methane required to increase the temperature of the air in the room by 7.35 °C is 7.95 g

The volume of air in the room is first calculated:

Volume of air in the room = 4.33 m x 3.43 m x 3.03 = 45.00 m³

1 m³ = 1000 L

45.00 m³ = 45.00 m³ * 1000 L/m³

Volume of air in L = 45000 L

Number of moles of air in 45000 L of air is then determined:

1.00 moles of air occupies 22.4 L

number of moles of air in 45000 L = 45000 L * 1 mole / 22.4 L

number of moles of air = 2008.93 moles of air

Energy that is needed to heat the room by 7.35 °C is then calculated:

Quantity of energy needed = Specific heat capacity * number of moles * temperature increase

Specific heat capacity of air = 30.0 J/K/mole

Quantity of energy needed = 30.0 * 2008.93 * 7.35

Quantity of energy needed = 442969.065 J = 443.00 kJ

The amount of methane required to produce that amount of energy is then calculated:

Equation of combustion of methane : CH₄ + 2 O₂  ---> CO₂ + 2 H₂O

Enthalpy of combustion of methane = −890.3 kJ/mole

Number of moles of methane required = 443.00 kJ / 890.8 kJ/mole = 0.497 moles

Mass of 1 mole of methane = 16.0 g

mass of 0.497 moles of methane = 16.0 * 0.497 = 7.95 g

Therefore, mass of methane required to increase the temperature of the air in the room by 7.35 °C is 7.95 g

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Answer:

Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence (outermost) electrons of one atom are transferred permanently to another atom.

Explanation: i took the same test

Answer:

it forms where a metal element and a non metal element react together to form a now compound

Answer:

1) SpongeBob’s question is that "what would be the appropriate way to wash his favorite pants as they don't seem as clean as earlier"?

2) SpongeBob’s claim that Clean-O detergent is unable to wash the pants more cleaner as compared to plain water.

3) Independent variable in the given example is the quantity of Clean-O detergent and plain water as it can be changed or manipulated.

4) Dependent variable in the given example is the cleanliness of pants as it will be affected by the quantity of Clean-O detergent and plain water which is an independent variable.

We know that carbon -14 is a radioactive isotope of carbon

It is used in carbon dating to know the age of different forms of dead organism including plants...

So it is used for estimating the age of sedimentry rocks which contains dead debris of plants and animals,

it can be produced from N14 by radioactive reaction of N-14 with neutron.

It is found in organisms

Answer:

Found in organisms remains.

Explanation:

Hope this helped

Answer: 1.13 x 10^5

Explanation:

Answer:

0.328 mol/dm³

Explanation:

We have

I started this calculation from Rate's law.

Remember equilibrium constant has been given to be 60%

Our interest is Kc, that is the equilibrium constant.

Ca = 4(1-0.6)/1+(-0.5*0.6)

= 4-2.4/1-0.3

= 1.6/0.7

= 2.2857

Cb = 4x0.6/2(1+(-0.5*0.6))

= 2.4/2(0.7)

= 2.4/1.4

= 1.7143

Kc = Cb/Ca²

= 1.7143/2.2857²

= 1.7143/5.2244

= 0.328 mol/dm³

I have added an attachment showing earlier stages to the final answer

Answer:

Electrons

Explanation:

This is because electrons barely contribute to the mass so only protons and neutrons are added.

Answer:

biological decay

Explanation:

Hope this helps

Answer:

The Inert Pair effect renders Pb(II) as the more stable oxidation state of lead

Explanation:

SnBr4 + PbBr2 ---> SnBr2 + PbBr4

SnBr2 + PbBr4 ---->

The Inert pair effect is mostly observed between group 15-17 in the periodic table. It leads to stability of the lower oxidation state of an element.

The reason for the Inert pair effect is that the s electrons become Inert due to poor shielding of the d and f-electrons. The Inert pair effect is a tendency of the s electrons not to participate in bonding (remain an Inert pair).

Owing to the Inert pair effect, Pb II is more stable than Pb IV

Answer:

K loses one electron to CI

Explanation:

The lewis electron dot notation shows only the chemical symbol of the element surrounded by dots to represent the valence electrons.

  We have atom of K with one valence electrons

   Cl with 7 valence electrons

For an electrostatic attraction to occur, both particles must be charged. To do this, one of the species must lose an electron, and the other gains it.

This will make both species attain a stable octet;

   Hence, K will lose 1 electron and Cl will gain the electrons.

Answer:

C: K loses one electron to CI

Explanation:

I took the test and got it correct!!

Answer:

1) first order

2) second order

3) zero order

Explanation:

The curve of a first order reaction shows it to be exponential. In fact for a first order reaction, the concentration at a time t is an exponential function;

[A]t= [Ao] e^-kt

Where

[A]t = concentration at time =t

[Ao]= initial concentration

k= rate constant

t= time

For a second order reaction, the rate of reaction is directly proportional to the concentration of reactants.

For zero order reactions, rate of reaction is independent of concentration hence rate = k(rate constant)

The concentration data has been required for the determination of the rate of reaction. Based on the concentration of reactant and product, the rate has been determined.

1. For the first-order reaction, there has been an exponential increase in the rate of the reaction with the increase in the reactant concentration. The rate has been dependent on the concentration of the reactant.

Thus the correct option is A.

2. Irrespective of the first-order kinetic, in the second-order reaction, the rate of reaction has been directly proportional to the concentration of the reactant in the solution.

Thus option B is correct.

3. The zero-order reaction has been independent of the concentration of the reactant. The rate of reaction has been constant with an increase in the reactant concentration.

Thus option C is correct.

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Answer:

The new pressure will be  

1000 L

, rounded to one significant figure.

Explanation:

Boyle's law states that when a gas is held at a constant temperature and mass in a closed container, the volume and pressure vary inversely. The equation to use is  

P

1

V

1

=

P

2

V

2

.

Given

V

1

=

200

mL

×

1

L

1000

mL

=

0.2 L

P

1

=

700 mmHg

V

2

=

100

mL

×

1

L

1000

mL

=

0.1 L

Unknown

P

2

Equation

P

1

V

1

=

P

2

V

2

Solution

Rearrange the equation to isolate  

P

2

and solve.

P

2

=

P

1

V

1

V

2

P

2

=

(

700

mmHg

×

0.2

L

)

0.1

L

=

1400 L

, which must be rounded to  

1000 L

because all of the measurements have only one significant figure

Explanation:

Finally, someone gave a clear photo.

Answer:

Metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids.

Explanation:

i hope this helps :)

Answer: Potassium Bromide (KBr) The Ionic bond formed between Potassium and Bromine is created through the transfer of electrons from Potassium (metal) to Bromine (nonmetal).

Explanation: this type of structure departs strongly from that expected for ionic bonding and ... whose roots go back to Max Planck's explanation in 1900 of the properties of ... types of interactions between elementary particles (the strong force, the weak force, ...

I'm not sure if this is the answer but maybe oil.

Answer:

Density of block of gold is 3.5 g/cm³.

Explanation:

Given data:

Volume of block = 1000 mL

Mass of block = 3.5 kg (3.5×1000 = 3500 g)

Density of block = ?

Solution:

Density of substance is calculated by dividing the mass of substance over its volume.

Formula:

d = m/v

d = 3500 g/ 1000 mL

d = 3.5 g/mL

or

d = 3.5 g/cm³             (1ml = 1cm³)

Answer: The answer is 5.15x10^22

Explanation:

The formula unit present in a teaspoon of salt [tex]NaCl[/tex] having a mass of about 5.0 g is [tex]5.15 \times10^{22}[/tex] formula units.

Molar mass, also known as molecular weight, is the mass of one mole of a substance. It is calculated by summing up the atomic masses of all the atoms in a molecule. The unit of molar mass is grams per mole (g/mol).

Now, to determine the number of formula units in a teaspoon of salt (NaCl), we need to use Avogadro's number and the molar mass of NaCl.

Avogadro's number [tex](N_a)[/tex] is approximately. [tex]6.022 \times10^{23}[/tex] formula units per mole.

The molar mass of [tex]NaCl[/tex] is the sum of the atomic masses of sodium (Na) and chlorine ([tex]Cl[/tex]), which are approximately 22.99 g/mol and 35.45 g/mol, respectively.

To calculate the number of formula units in 5.0 g of [tex]NaCl[/tex], we can follow these steps:

Now, calculate the number of moles of [tex]NaCl[/tex] using its molar mass:

Moles = Mass / Molar mass

Moles = [tex]5.0 g[/tex] / [tex](22.99 g/mol + 35.45 g/mol)[/tex]

Calculate the number of formula units using Avogadro's number:

Formula units = [tex]Moles \times Avogadro's number[/tex]

Let's perform the calculation:

Molar mass of [tex]NaCl[/tex]= [tex]22.99 g/mol + 35.45 g/mol = 58.44 g/mol[/tex]

Moles of [tex]NaCl[/tex] = [tex]5.0 g[/tex] / [tex]58.44 g/mol[/tex] ≈ [tex]0.0856 mol[/tex]

Formula units = [tex]0.0856 mol \times (6.022 \times 10^{23})[/tex] formula units/mol ≈ [tex]5.15 \times10^{22}[/tex]formula units.

Therefore, there are approximately [tex]5.15 \times10^{22}[/tex] formula units in a teaspoon of salt ([tex]NaCl[/tex]) having mass [tex]5.0 g[/tex].

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Answer:

mass = density × volume = 0.67 × 1.00 = 0.67 kg = 670 g. The molar mass of octane, C8H18, is 8 × 12.01 (C) + 18 × 1.008 (H) = 114.224.

Explanation:

Answer:

Explanation:

Noble gas notation: [Xe] 6s2

Complete Electron Configuration: 1s22s22p63s23p63d104s24p64d105s25p66s2.

(ik kinda hard to understand but i looked it up ant it works)

Answer:

Complete Electronic Configuration:

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²

Electronic Configuration in Noble Gas Notation:

[Xe] 6s²

Answer:

atom

Explanation:

the atom is the smallest form.

Metals typically lose electrons to complete their octet in a reaction with non-metals, whereas non-metals typically acquire electrons to complete their octet. Ionic compounds are typically formed via reactions between metals and nonmetals. The given compound barium hydroxide is ionic.

Ions with the opposite charge are carefully packed together to form crystalline solids. Ionic compounds typically result from reactions between metals and non-metals. The electrostatic interaction between the positive and negative ions holds ionic solids together.

Baryta, commonly known as barium hydroxide, has the chemical formula Ba(OH)₂. It is an odorless, clear-white powder. It has a toxic disposition. It is ionic in nature, with two hydroxide ions per molecule of barium hydroxide (Ba(OH)₂ in an aqueous solution an example.

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Answer : The number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.

Explanation : Given,

Concentration of NaBr = 0.200 M

Volume of solution = 100.0 mL = 0.1 L      (1 L = 1000 mL)

First we have to calculate the moles of NaBr.

[tex]\text{Moles of NaBr}=\text{Concentration of NaBr}\times \text{Volume of solution in L}[/tex]

[tex]\text{Moles of NaBr}=0.200M\times 0.1L=0.02mol[/tex]

Now we have to calculate the moles of precipitate, [tex]PbBr_2[/tex] formed.

The balanced chemical reaction is:

[tex]2NaBr(aq)+Pb(NO_3)_2(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)[/tex]

From the balanced chemical reaction we conclude that:

As, 2 moles of NaBr react to give 1 mole of [tex]PbBr_2[/tex]

So, 0.02 moles of NaBr react to give [tex]\frac{0.02}{2}=0.01[/tex] mole of [tex]PbBr_2[/tex]

Therefore, the number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.

The number of mole of the precipitate (i.e PbBr₂) formed when 100 mL of 0.2 M NaBr react with excess Pb(NO₃)₂ is 0.01 mole

Volume = 100 mL = 100 / 1000 = 0.1 L

Molarity of NaBr = 0.2 M

Mole = Molarity x Volume

Mole of NaBr = 0.2 × 0.1

2NaBr(aq) + Pb(NO₃)₂(aq) → PbBr₂(s) + 2NaNO₃ (aq)

From the balanced equation above,

2 moles of NaBr reacted to produce 1 mole of PbBr₂.

Therefore,

0.02 mole of NaBr will react to produce = [tex]\frac{0.02}{2} \\\\[/tex] = 0.01 mole of PbBr₂.

Thus, the number of mole of the precipitate (i.e PbBr₂) produced from the reaction is 0.01 mole

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Answer:

Explanation:

80

Answer: here is your answer

Explanation: You are visiting your Grandmother and notice that she is eating a balanced diet, taking vitamins, getting the proper amount of sleep and is not overweight. Despite her healthy lifestyle, she appears run down and tired. You realize that it's due to her lack of physical activity. Write a convincing letter to your grandma explaining the benefits of participating in regular physical activity.

Answer:

713 nm. It is not visible with the naked eye.

Explanation:

Step 1: Given data

Step 2: Calculate the wavelength of the light

We will use the Planck-Einstein equation.

E = h × c / λ

λ = h × c / E

λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 2.79 × 10⁻¹⁹ J

λ = 7.13 × 10⁻⁷ m

Step 3: Convert "λ" to nm

We will use the relationship 1 m = 10⁹ nm.

7.13 × 10⁻⁷ m × (10⁹ nm/1 m) = 713 nm

This light is not in the 400-700 nm interval so it is not visible with the naked eye.