A sample of a compound is added to distilled water in a clean beaker. A reaction occurs
and the water temperature drops rapidly. Which of the following statments best supports this
observation?

A. An endothermic reaction occurred

B. The water was originally warmer than the compound

C. An exothermic reaction occurred

D. The beaker was contaminated by another compound

Answer:

3.45 L

Explanation:

Temperature and volume are linearly related (when one increases or decreases, so does the other).

Convert the temperature to Kelvin:

50 °C = 323 K

100 °C = 373 K

To find the rate of change, divide 373 by 323 to get roughly 1.15

Multiply the amount of liters by this factor to get your answer

Answer:

SOUND WAVE (carried by thin metal inside the phone) ⇒ELECTRICAL ENERGY (over the wire) ⇒SOUND WAVE (that is heard by someone on the side of the phone)

Explanation:

A wave that is comprised of compression and refraction, by which sound is propagated in an elastic medium such as air.

The sound waves are carried to a thin metal disk inside the phone, known as the diaphragm, and are converted into electrical energy. The electrical energy travels over wires to another phone and is converted from electrical energy to sound waves again which can be heard by the one on the other end of the phone.

In this way, sound reaches our ears.

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Answer:

Explanation:

The pH of a solution can be found by using the formula

[tex]pH = - log ([ {H}^{+} ])[/tex]

From the question

[H+] = 0.045 M

We have

[tex]pH = - log(0.045) \\ = 1.346787...[/tex]

We have the final answer as

Hope this helps you

Answer:

1.35

Explanation:

Answer:

Probably around 6 because the ph of hydrochloric acid is 3

Explanation:

Answer:

80L

Explanation:

V1/T1 = V2/T2

V2 = V1 T2/T1

T1 = 300K

V1 = 60L

T2 = 400K

V2 = ?

V2 = V1 T2/T1

V2 = (60L)(400K) / (300K)

V2 = 80L

Answer:

[tex]Al_2(SO_4)_3+3Mg(NO_3)_2\rightarrow 2Al(NO_3)_3+3MgSO_4[/tex]

Explanation:

Hello there!

In this case, for the given reactants side, we infer this is a double replacement reaction because all the cations and anions are switched around as a result of the chemical change, we infer that the products side include aluminum with nitrate and magnesium with sulfate as shown below:

[tex]Al_2(SO_4)_3+Mg(NO_3)_2\rightarrow Al(NO_3)_3+MgSO_4[/tex]

However, we need to balance since unequal number of atoms are present at both sides, thus, we do that as shown below:

[tex]Al_2(SO_4)_3+3Mg(NO_3)_2\rightarrow 2Al(NO_3)_3+3MgSO_4[/tex]

Thus, we make 6 Al atoms, 3 S atoms, 3 Mg atoms and 30 O atoms on each side in agreement with the law of conservation of mass.

Regards!

Answer:

Lava flows are streams of molten rock that pour or ooze from an erupting vent. Lava is erupted during either nonexplosive activity or explosive lava fountains. ... But when basalt lava flows are confined within a channel or lava tube on a steep slope, the main body of the flow can reach velocities >30 km/h (19 mph).

Explanation:

As the bodies present in the gravitational force of sun, so it is appropriate to describe the sun and its celestial bodies as system.

Celestial bodies are those objects which are present in the space not in the land.

In the space all the planets are present in their orbitals under the gravitational force of the sun and do the motion around the sun, because of that force planets are present in the orderly arrangement. Because of the revolution of the earth around the sun, seasons will change on the earth.

Hence, it is appropriate to describe the sun and its celestial bodies as system.

To know more about celestial bodies, visit the below link:

https://brainly.com/question/3735999

Explanation:

The new pressure can be found by using the formula for Boyle's law which is

[tex]P_1V_1 = P_2V_2 \\[/tex]

Since we're finding the new pressure

[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]

We have

[tex]P_2 = \frac{25 \times 1}{125} = \frac{25}{125} = \frac{1}{5} = 0.2 \\ [/tex]

We have the final answer as

Hope this helps you

Answer:

B. 4Na + O2 → 2Na2O

Explanation:

Got it right on the test :)

For balanced  equation the mass of reactant is exactly equal to the mass of product. atoms of reactant equal to the atoms of product is called as balanced equation.

The law of conservation of mass, which states that "the total mass of all the products of reaction in a chemical reaction is equal to the total mass of all the reactants," is satisfied by balancing chemical equations.

A balanced chemical equation, in which the masses of the reactants and products are equal, contains the same amount of atoms of each element on both sides of the equation.

4Na + O₂ ⇒  2Na₂O₂

In this reaction in reactant there are four number of sodium atom and in product also four number of sodium atom. Similarly total number of oxygen at reactant is equal to the total number of oxygen at product.

Thus, option B is correct.

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Answer:

1.66 basic

Explanation:

Answer:

The relative molecular mass of ammonium nitrate is 80 gm

Explanation:

[tex]M_{NH4NO3}[/tex] = 14 + (4 × 1) + 14 + (16 × 3) = 80 (gm)

Answer:

pH = 3.42

Explanation:

Para calcular el pH necesitamos usar la siguiente expresión:

pH = -log[H⁺]

Por tanto, solo necesitamos reemplazar el valor dado de [H⁺] en la expresión anterior y se determina su pH:

pH = -log(3.8x10⁻⁴)

Por tanto el pH de la muestra de jugo de limón es 3.42

Answer:

1.49kJ

Explanation:

Using the formula as follows;

Q = m × c × ∆T

Where;

Q = amount of heat (joules)

m = mass (g)

c = specific heat of silver (J/g°C)

∆T = change in temperature (°C)

According to the information given in this question;

mass of Silver (Ag) = 236g

c of Ag = 0.24 J/g°C

initial temperature (T1) = 8.5°C

final temperature (T2) = 34.9°C

∆T = T2 - T1 = 34.9 - 8.5 = 26.4°C

Using Q = m × c × ∆T

Q = 236 × 0.24 × 26.4

Q = 1,495.3 Joules

Amount of heat needed to raise the temperature of Silver (Q) in kilojoules is 1495.3/1000 = 1.4953

Q = 1.49kJ

Answer:

true

Explanation:

Explanation:

One atom of carbon (2.4) combines with two atoms of oxygen (2.6) to form the compound carbon dioxide CO2 (only the outer shell of carbon's electrons are shown). ... The carbon dioxide molecule is held together by the strong C=O. carbon–oxygen double covalent bonds by sharing electrons.

Answer:

C

Explanation:

Answer: The value of equilibrium constant, K, is [tex]7.74 \times 10^{-4}[/tex].

Explanation:

The reaction equation is as follows.

[tex]2SO_{3}(g) \rightleftharpoons 2SO_{2}(g) + O_{2}(g)[/tex]

Now, the expression for equilibrium constant of this reaction is as follows.

[tex]K = \frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}[/tex]

Substitute the given values into above expression as follows.

[tex]K = \frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}\\= \frac{(\frac{0.210}{15.4})^{2} \times (\frac{0.354}{15.4})}{(\frac{8.51 \times 10^{-2}}{15.4})}\\= 7.74 \times 10^{-4}[/tex]

Thus, we can conclude that the value of equilibrium constant, K, is [tex]7.74 \times 10^{-4}[/tex].

Explanation:

Your chemical equation should look like this:

Li3PO4 + AlF3 --> 3LiF + AlPO4

This is the balanced equation for a double-displacement reaction

Answer: The reactivity of group 1 elements increases as you go down the group because: the atoms become larger. the outer electron becomes further from the nucleus. the force of attraction between the nucleus and the outer electron decreases.

Answer:

im not a brain wiz but i think 20

Explanation:

Answer:

0.274 L

Explanation:

Applying Boyle's law,

PV = P'V'................. Equation 1

Where P = Initial pressure, V = Initial volume, P' = Final pressure, V' = Final volume.

make V' the subject of the equation,

V' = PV/P'............. Equation 2

From the question,

Given: P = 500 mm Hg, V = 500 mL = 0.5 L, P' = 1.2 atm = 912 mm Hg

Substitute these values into equation 2

V' = (0.5×500)/912

V' = 0.274 L

Hence the new volume is 0.274 L

Answer:

cell :—

•They lack a well-defined nucleus, have a nucleoid instead.

•Usually have double-stranded, circular DNA.

•Do not have mitochondria.

Eukaryotic cell :—

•Have a well-defined nucleus enclosed in the nuclear membrane.

•Have a linear double-stranded nucleus.

•Mitochondria are present.

Answer:

The temperatures on Earth increase

Explanation:

more energy results in more heat.

gene therapy

Explanation:

Gene therapy, also called gene transfer therapy, the introduction of a normal gene into an individual's order to repair a mutation that causes a genetic disease.

Answer:

C artificial selection

Explanation:

Brainly please

D melting ice cream because if u know what a physical change is its a change that you can reverse chimical change are changes you cant reverse so u can freeze back ice cream so :D

Answer:

Very true

Explanation: