An electron in the n=7 level of the hydrogen atom relaxes to a lower energy level, emitting light of 93.1 nm.
What is the value of n for the level to which the electron relaxed?

For cigarette lighters containing liquid butane, C4H10, the quantity of heat produced  is mathematically given as

q= -49.2 KJ

Generally, the equation for the Chemical reaction   is mathematically given as

C₄H₁₀(l) + 6.5 O₂(g)---->4 CO₂(g) + 5 H₂O(l)

Therefore

dH°r = .(-393.5 ) + 5.(-285.5] - [1.(-147.6 )+6.5.

dH°r = -2853.9 kJ/mol

In conclusion, No.of mole

Nm = 1g/58g/mol

Nm= 0.01724mol

Hence, Heat of combustion

q = dH°r x moles

q = -2853.9 ×0.01724

q= -49.2 KJ

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Answer:

2,2,3-trimethylpentane

Explanation:

The iupac name for the compound shown is 2,2,3-trimethylpentane

Answer:

9 gram of H2O can be produced

Answer:

Without angiosperms, average annual rainfall in the area declined by 300 millimeters. In the eastern Amazon basin, the length of the wet season decreased by nearly 3 months. The extent of the wettest rainforests, which receive more than 100 millimeters of rain per month, shrank by 80%.

Ideal gas law:  PV = nRT

Write down what you know and what you want to fine:

P = pressure = ?

V = volume in liters = 0.950 L

n = moles = 727.2 g x 1 mol CH4 / 16 g = 45.45 moles

R = gas constant = 0.0821 Latm/Kmol

T = temperature in K = 221.9K

Solve for P:

P = nRT/V = (45.45)(0.0821)(221.9) / 0.950

P = 872 atm (3 sig. figs. based on 0.950 L having 3 s.f.)

Answer:

E

Explanation:

Recall the Henderson-Hasselbalch equation:

[tex]\displaystyle \text{pH} = \text{p}K_a + \log \frac{[\text{Base}]}{[\text{Acid}]}[/tex]

For a pH of 5.14 with the given pKa of 4.74, solve for the ratio between acetate and acetic acid:

[tex]\displaystyle \begin{aligned} (5.14) & = (4.74) + \log\frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]} \\ \\ \log\frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]}& = 0.40 \\ \\ \frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]} & = 10^{0.40} \\ \\ & = 2.5\end{aligned}[/tex]

In conclusion, the answer is E.

The statement which gives you enough information to say that the atom is electrically neutral is: The atom has 7 protons and 7 electrons.

Answer:

120 calories

Explanation:

Calories and nutrition for world population. One tablespoon of palm oil has 120 calories and 13.6 grams of fat. What does it tell you? Of the 13.6 grams of fat in a tablespoon of palm oil, 6.7 grams are saturated and 6.3 grams are unsaturated.

In chemistry, “partial pressure” refers to the pressure that each gas in a gas mixture exerts against its surroundings, such as a sample flask, a diver’s air tank, or the boundary of an atmosphere. You can calculate the pressure of each gas in a mixture if you know how much of it there is, what volume it takes up, and its temperature. You can then add these partial pressures together to find the total pressure of the gas mixture, or, you can find the total pressure first and then find the partial pressures.

Answer:

[tex] \boxed{ \sf \: m = 1.866 \: grams}[/tex]

Explanation:

Given:

Change in temperature ∆T= -74.14°C

Heat(Energy) released Q= 578.7 joules

Specific heat capacity s = 4.184 J/(g·°C)

To find:

Mass of the sample (m)=?

Solution:

[tex] \sf s= \frac{Q}{m \cdot \Delta T} \\ \sf \: Substituting \: the \: given \: parameters \\ \sf 4.184 = \frac{578.7}{m \times ( - 74.14)} \\ \sf m = \frac{578.7}{4.184 \times ( - 74.14)} \\ \sf m = \frac{578.7}{310.20176} \\ { \sf m = 1.8655 \approx1.866 \: grams}[/tex]

Since, we need the answer in 4 significant figures,

[tex] \boxed{ \sf \: m = 1.866 \: grams}[/tex]

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66.9 grams of CO₂ ( Carbon dioxide gas ) will be required to exert the given value of pressure at the given volume and temperature.

The Ideal gas law or general gas equation emphasizes on the state or behavior of a hypothetical ideal gas. It states that "the pressure multiplied by volume is equal to moles multiply by the universal gas constant multiply by temperature.

It is expressed as;

PV = nRT

Where P is pressure, V is volume, n is the amount of substance, T is temperature and R is the ideal gas constant ( 0.08206 Latm/molK )

Given the data in the question;

To determine the amount of gas, we substitute our values into the expression above.

PV = nRT

n = PV / RT

n = ( 1.01184atm × 52.3L ) / ( 0.08206Latm/molK × 425K )

n = 52.919232Latm / 34.8755Latm/mol

n = 1.52mol

Now, we the mass of CO₂ ( Carbon dioxide gas ).

Molar mass of CO₂ is 44.01 g/mol

Hence;

1.52mol × 44.01 g/mol = 66.9g

Therefore, 66.9 grams of CO₂ ( Carbon dioxide gas ) will be required to exert the given value of pressure at the given volume and temperature.

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The third picture is the answer

Explanation:

there are 2 hydrogen atom 1 oxygen

Answer:

B

Explanation:

From the given chemical equation, we want to determine the mass of arsenic necessary to produce 15.0 mL of 0.0852 M H₂AsO₄⁻.

Find the amount of moles present in 15.0 mL of 0.0852 M H₂AsO₄⁻ solution. Recall that M = mol/L:

[tex]\displaystyle 15.0\text{ mL} \cdot \frac{0.0852\text{ mol H$_2$AsO$_4^-$}}{1\text{ L}} \cdot \frac{1\text{ L}}{1000\text{ mL}} = 0.00128\text{ mol H$_2$AsO$_4^-$}[/tex]

With stoichiometric ratios and molecular weights, determine the mass of arsenic necessary:

[tex]\displaystyle 0.00128 \text{ mol H$_2$AsO$_4^-$} \cdot \frac{8\text{ mol As}}{3\text{ mol H$_2$AsO$_4^-$}}\cdot \frac{74.92\text{ g As}}{1\text{ mol As}} = 0.256\text{ g As}[/tex]

In conclusion, the answer is B.

From the statement and the information available in the question, the pH of the solution is 12.2.

The term Ka refers to the acid dissociation constant of a substance, we can obtain this by setting up the ICE table as shown;

       C6H5O^-  +   H2O ⇄  C6H5OH + OH^-

I         0.250                           0                0

C         -X                                +X             +X

E      0.250 -x                         x                x

Now;

Kb = 1 * 10^-14/ 1.0 x 10-10

Kb = 1 * 10^-4

Kb = [C6H5OH] [OH^-]/[C6H5O^-]

1 * 10^-4 = x^2/ 0.250 -x

1 * 10^-4 (0.250 -x) = x^2

2.5 * 10^-4 - 1 * 10^-4 x = x^2

x^2 + 1 * 10^-4 x  - 2.5 * 10^-4 = 0

x=0.016 M

Given that; [C6H5OH] = [OH^-] =x

pOH = -log(0.016 M) = 1.8

pH = 14 - 1.8 = 12.2

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Answer:

b) Li2S(aq)+Pb(NO3)2(aq)

e) K2S(aq)+Sn(NO3)4(aq)

Explanation:

they are the only two of the options that contain a sulfide ion (S) therefore they are the only ones that could be considered in the question.

b) Li2S(aq)+Pb(NO3)2(aq)

e) K2S(aq)+Sn(NO3)4(aq)

Answer:

Gyanendra of Nepal

Explanation:

It is the unit of work or energy

Answer:

1 molecule of Ca(NO3)2 has 6 oxygen atoms.

Answer:

(A) Nickels and pennies

Answer:yes is yes = 0iq

Explanation: hes was a prodogy he helped alot of people -500iq

Answer:

1124.2

Explanation:

just easy mathamatics

Answer:

=3 means is 3 or greater so that would be f and g subshells

=0 means is 0 or greater so that would be s, p, d, f and g subshells

=1 means is 1 or greater so that would be p, d, f, and g subshells

=4 means is 4 or greater so that would be g only

Answer:

The amount of grams of Cu that reacted is 18.15g

Explanation:

Where:.

Cu= 63.5

O= 16

N= 14

Molar mass of Cu(NO3)2 =

63.5 + 2(14+ 48)

63.5 + 124

=187.5

THEN IF 63.5g of Cu reacted in 187.5g of Cu(NO3) 2

x of Cu is in - - - - >53.6g

x= 63.5 * 53.6/187.5

x= 3403.6/187.5

x= 18.15g of Cu reacted.

Answer:

try doing a math problem it may help

Explanation:

Answer:

acid-base neutralization

Explanation: When a base and acid react, it neutralizes the substance making it a neutral substance, which is water and a salt

Thermodynamics is the science that deals with work, temperature and heat. It studies the energy of motion and heat. Thus, option C is accurate.

Thermodynamics, thermo means heat and energy and dynamics means motion or movement. It is a branch of science that relates the entropy, enthalpy, and motion of matter.

It is used in physics and chemistry to depict the change in the system influenced by the surrounding. The release or the gain of heat in a thermodynamic system is studied as well.

Therefore, in option C the energy of motion and heat are studied in thermodynamics.

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Answer:

In the following reaction, how many moles of

CO2

can be made by reacting 0.50 moles of

CH4

with excess oxygen?

CH4+O2>CO2+H2O

Explanation:

Answer:

eight

Explanation:

That means there are 12 electrons in a magnesium atom

hope this helps