4. What is the specific heat of a substance if 5800 joules is
released in a 250 gram sample that will cool the substance from
60 degrees to 45 degrees?

Answer:

3, 9, 3

Explanation:

The coefficient of 3 tells us that there are three molecules (the chemical unit of NH3). Each molecule of ammonia (NH3) is made up of 1 atom of nitrogen bonded to 3 atoms of hydrogen.

Since there are three molecules, we have three times the amount of atoms there are in one molecule.

3 x 1 = 3 nitrogen

3 x 3 = 9 hydrogen

Answer:

a. pH = 7.0

b. pH = 12.52

c. pH = 12.70

d. pH = 12.78

Explanation:

a. Deionized water has the [H⁺] of pure water = 1x10⁻⁷ (Kw = 1x10⁻¹⁴ = [H⁺][OH⁻] - [H⁺] = [OH⁻ -)

pH = -log[H⁺] = 7

b. Moles NaOH = 5x10⁻³L * (0.10mol / L) = 5x10⁻⁴moles OH⁻ / 0.015L = 0.0333M = [OH⁻]

-Total volume = 10mL+5mL = 15mL = 0.015L

pOH = -log[OH⁻] = 1.48

pH = 14-pOH

pH = 12.52

c. Moles NaOH = 0.010L * (0.10mol / L) = 1x10⁻³moles OH⁻ / 0.020L = 0.0500M = [OH⁻]

-Total volume = 10mL+10mL = 20mL = 0.020L

pOH = -log[OH⁻] = 1.30

pH = 14-pOH

pH = 12.70

d. Moles NaOH = 0.015L * (0.10mol / L) = 1.5x10⁻³moles OH⁻ / 0.025L = 0.060M = [OH⁻]

-Total volume = 10mL+15mL = 25mL = 0.025L

pOH = -log[OH⁻] = 1.22

pH = 14-pOH

pH = 12.78

Answer:

Yes. At least some. There has been ups and downs in temperature ever since the Earth was created, and this is just another up in temperature. I do think that humans have made it worse though, with all of the greenhouse gases and things like that.

A severe storm would be most likely to damage a coastal area by causing pollution. Therefore, the correct option is option B.

The region where land joins the ocean, or even as a line defining the border between the land as well as the shoreline, is known as the coast, sometimes referred as the coastline and seashore. The terrain of the area's surroundings has an impact on shorelines, as do water-induced erosion processes like wave action.

The length of the shoreline on Earth is about 620,000 kilometers. Natural ecosystems' coasts are significant zones and frequently the site of a diverse range of biodiversity. They are home to significant ecosystems on land, such as freshwater and estuarine wetlands, that are crucial for the survival of bird populations or other land animals. A severe storm would be most likely to damage a coastal area by causing pollution.

Therefore, the correct option is option B.

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the first one is A covalent bond.

the second one is Answer: B Decomposition

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 8.12×10²³ atoms are in  90.43 mole of copper.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample. There are so many formula for calculating mole.

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles of copper=90.43 moles

Substituting all the given values in the above equation, we get

number of atoms/molecules= 90.43 × 6.022×10²³

number of atoms/molecules=8.12×10²³ molecules

Therefore, 8.12×10²³ atoms are in 90.43 mole of copper.

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Answer:

HPRT

Explanation:

HPRT catalyzes the salvage reactions of hypoxanthine and guanine with PRPP to form IMP and GMP

The formation of GMP from IMP requires oxidation at C-2 of the purine ring, followed by a glutamine-dependent amidotransferase reaction that replaces the oxygen on C-2 with an amino group to yield 2-amino,6-oxy purine nucleoside monophosphate, or as this compound is commonly known, guanosine monophosphate.

The equilibrium partial pressure of HF is 0.55 atm.

The equation of the reaction is;

        H2(g) + F2(g) ⇄ 2HF

I         2           1             0

C       -x           -x            +x

E     2 - x        1 - x           x

We know that;

pH2 = 2.0 atm

PF2 =  1.0 atm

pHF = ??

Kp = 0.45

So;

Kp = (pHF)^2/pH2. pF2

0.45 = x^2/(2 - x) (1 - x)

0.45 =  x^2/x^2 - 3x + 2

0.45(x^2 - 3x + 2) = x^2

0.45x^2 - 1.35x + 0.9 =  x^2

0.55 x^2 + 1.35x - 0.9 = 0

x = 0.55 atm

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Answer:

B : 0.133 M

Explanation:

moles Li3N3 = 0.4 mol Li x (2 moles Li3N/6 moles Li) = 0.133 M