If 6.75 g of NaOH are dissolved in 50.00 g of water and the temperature increases from 20.5°C to 47.8 °C.

a. Is this an example of an endothermic or exothermic reaction?

b. What is the q for the reaction? (Remember since the NaOH dissolves in water add the masses to get the m)

c. How many moles of NaOH are dissolved?

d. What is the ΔH for the reaction?

Answer:

As organisms release energy during cellular respiration, carbon dioxide is produced from the carbon in energy storage molecules. ... Carbon dioxide in the biodome decreased because decomposers decreased which means there was a decrease in cellular respiration overall.

Explanation:

Carbon dioxide is "a colorless, odorless gas that is present in the atmosphere and is formed when any fuel containing carbon is burned".

Atmosphere is "a mixture of gases that includes about 78% nitrogen and 21% oxygen at Earth's surface".

Fuel is "a substance which upon combustion produces a usable amount of energy".

When the population of decomposer decreased, the amount of carbon dioxide in the biodome decreased drastically. The carbon dioxide that used to be in the air (abiotic matter) is now in another part of the ecosystem and the carbon remained constant.

Hence, Carbon dioxide decreased in the air (abiotic matter) of the biodome.

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Answer:

8

Explanation: # of protons = atomic #

Answer:

Place a glass rod in the solution, if the crystallisation point has been reached, you should notice small crystals formed on it.

Answer:

The correct answer is 1.21 L.

Explanation:

Based on the given information, the reaction will be,

CS2 (l) + 3Cl2 (g) ⇒ CCl4 (l) + S2Cl2 (l)

By using the standard values of the substances, the standard enthalpy of the reaction is,

ΔH° = [(-139.5) + (-58.5) – 0 – (87.3)] kJ/mol

= -285.3 kJ/mol

The amount of heat evolved for 3 moles of chlorine reacted us 285.3 kJ.

Now the number of moles of chlorine needed to react to produce 5.00 kJ is,

= 5.00 kJ × 3 mol Cl2/285.3 kJ

= 0.0526 mol Cl2

Now the volume of chlorine gas at 27degree C and 812 mmHg will be,

Volume = 0.0526 mol Cl2 × 0.0821 Latm/mol K × 300 K/ 1.07 atm

= 1.21 L

Answer:

Baking Soda is NaHCO3 ---Sodium hydrogen Carbonate

Excessive use of Fertilizer can cause plants to develop shallow root systems,Decrease soil fertility and reduce Quality of Crops.

Answer:

Sodium bicarbonate, also called sodium hydrogen carbonate, or bicarbonate of soda,  is a source of carbon dioxide and so is used as an ingredient in baking powders, in effervescent salts and beverages, and as the main constituent of dry-chemical fire extinguishers.

Explanation:

Answer:

A molecule is the smallest particle of a substance that is made up of 2 or more atoms

An atom is the smallest particle of any pure element

An element is a substance that cannot be broken chemical and physical processes

A molecule is known as the building block of matter

A compound is a chemical substance that is made up of 2 more more different atoms bonded together

Answer: Aluminum, because it allows heat to flow easily.

Have a nice day!

Answer:

I think:

CH3COCH2CH2CH3 belongs to ketone because it has a carbonyl group C=O in its structure.

AAnswer:

Explanation:

Answer:

more electron deficient

Explanation:

The nitro group is an electron withdrawing group. It withdraws electrons from the pyridine ring by resonance.

This electron withdrawal by resonance makes the pyridine ring less electron rich or more electron deficient.

Hence, the nitro group makes the pyrinde ring more electron deficient

Answer:

I think the answer would be A.

Answer:

1.53 atm

Explanation:

From the question given above, the following data were obtained:

Volume = constant

Initial pressure (P₁) = stp = 1 atm

Initial temperature (T₁) = 273 K

Final temperature (T₂) = 144 °C = 144 °C + 273 = 417 K

Final pressure (P₂) =?

Since the volume is constant, the final pressure can be obtained as follow:

P₁ / T₁ = P₂ / T₂

1 / 273 = P₂ / 417

Cross multiply

273 × P₂ = 417

Divide both side by 273

P₂ = 417 / 273

P₂ = 1.53 atm

Therefore, the final pressure (i.e the pressure inside the hot water bottle) is 1.53 atm.

Answer:

HNO3 is a potent acid, a base, a nitrating agent and a heavy oxidising agent at times. In the presence of a stronger acid, it serves as a base.

Explanation:

Answer:

It is a strong acid

Explanation:

Answer:

The answer is "the electron configuration of the element".

Explanation:

Electronics are distributed in atomic and molecular orbit via electrons from an atom or a molecule.

It reflects a most frequent dependence on valence electrons in the outer.

Through analyzing the context of the regular periodic table, the individual atoms are helpful. That's also important to understand chemical connections, which hold electrons together. This similar approach helps to explain the specific characteristics of lasers or semiconductors for bulk materials.

We know that [OH⁻] * [H⁺] = 10⁻¹⁴

plugging the value of [H⁺]

[OH⁻] * 1.2 * 10⁻³ = 10⁻¹⁴

[OH⁻] = 10⁻¹⁴ * (10³/1.2)

[OH⁻] = 833.3 * 10⁻¹⁴

[OH⁻] = 8.33 * 10⁻¹²

Answer:

1) donate an H+ ion

Explanation:

option 1 is correct

Answer:

Therefore, it can be said that sugar molecules whether in crystal or cube form do not dissolve in ice tea.

Explanation:

Sugar molecules easily dissolve in warm or hot tea. However, in iced tea sugar does not dissolve it does not matter whether you use sugar cubes or sugar crystals.

This happens because of the entropy. The entropy of warm water is high as it has fast-moving molecules, whereas the entropy of ice water is negligible. hence, sugar molecules do not dissolve in ice tea.

Therefore, it can be said that sugar molecules whether in crystal or cube form do not dissolve in ice tea.

Answer:

If reactant or product is removed, the equilibrium shifts to make more reactant or product, respectively, to make up for the loss.

If the reactant or product is removed, the equilibrium shifts to make more reactant or product, to make up for the loss.

When the concentration of the HCl is varied, the color of the solution is changed as the equilibrium position moves to the left or right.

The term equilibrium in a chemical reaction connotes that the forward and the revers reactions proceed at the same rate. Let us note that Co(H2O)6^2+ is pink in color while  CoCl4^2– is blue in color.

As such, when the concentration of the HCl is varied, the color of the solution is changed as the equilibrium position moves to the left or right.

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Two airplanes are flying in the sky in such a way that the gravitational attractions between them decreases. The planes must be flying away from each other. Hence option A is correct.

Gravitational attraction is defined as a basic interaction that pulls everything with mass or energy in the same direction. All objects are subject to gravitational interactions, the strength of which is directly inversely proportional to the product of their masses. The size of an object and the separation between the objects have an impact on gravity.

In order to reduce the gravitational pull, two planes are flying in the sky. There must be a directionality between the aircraft. No matter what is in between the two bodies, there will still be gravitational pull. As a result, even if the medium between the two bodies changed, the gravitational force between them would not.

Thus, two airplanes are flying in the sky in such a way that the gravitational attractions between them decreases. The planes must be flying away from each other. Hence option A is correct.

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Answer:

6 moles

Explanation:

because if conducting a moles ratio for oxygen and water it is 1:2 so the moles would calculate up to 6 moles after cross multiplication.

Answer:

its option 3

Explanation:

the molarity of the solution increases

If more powdered Kool-Aid is added to the same amount of water, then the molarity of the solution increases because there are more solute particles in the solution.

Molarity of a given solution is known as the total number of moles of solute per litre of the solution.  A solution that is 1.00 molar (written 1.00 M) contains 1.00 mole of solute for every liter of solution.

Molarity = (No. of moles of solute ÷ Volume of solution in liters)

The unit of molarity is mol L⁻¹.

Molarity is temperature dependent because as temperature changes, volume of the solution also changes.

Therefore, If more powdered Kool-Aid is added to the same amount of water, then the molarity of the solution increases because there are more solute particles in the solution.

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Answer: The volume of given container is 3.83 L.

Explanation:

Given: Mass of [tex]H_{2}[/tex] = 0.224 g

Mass of [tex]N_{2}[/tex] = 1.06 g

Mass of Ar = 0.834 g

Since, moles is the mass of a substance divided by its molar mass. Therefore, moles of given substances present in the mixture are as follows.

Moles of  [tex]H_{2}[/tex] are:

[tex]Moles = \frac{mass}{molar mass}\\= \frac{0.224 g}{2 g/mol}\\= 0.112 mol[/tex]

Moles of [tex]N_{2}[/tex] are:

[tex]Moles = \frac{mass}{molar mass}\\= \frac{1.06 g}{28 g/mol}\\= 0.038 mol[/tex]

Moles of Ar are:

[tex]Moles = \frac{mass}{molar mass}\\= \frac{0.834 g}{40 g/mol}\\= 0.021 mol[/tex]

Total moles = (0.112 + 0.038 + 0.021) mol = 0.171 mol

Now, using ideal gas equation the volume is calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

[tex]V = \frac{nRT}{P}\\= \frac{0.171 mol \times 0.0821 L atm/mol K \times 273 K}{1 atm}\\= 3.83 L[/tex]

Thus, we can conclude that the volume of given container is 3.83 L.

Answer:

Explanation:

PCl3, the octet for both phosphorus and Chlorine atoms is complete. Therefore, it follows the octet rule.

Answer: The half-reactions represents reduction are as follows.

Explanation:

A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element  takes place is called reduction-half reaction.

For example, the oxidation state of Cr in [tex]Cr_{2}O^{2-}_{7}[/tex] is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.

[tex]Cr_{2}O^{2-}_{7} + 3 e^{-} \rightarrow Cr^{3+}[/tex]

Similarly, oxidation state of Mn in [tex]MnO^{-}_{4}[/tex] is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.

[tex]MnO^{2-}_{4} + 5 e^{-} \rightarrow Mn^{2+}[/tex]

Thus, we can conclude that half-reactions represents reduction are as follows.

Answer:

TRUE ,hope it helped you

Explanation:

Answer:

a. 0.4539g benozic acid

b. 60.29% of benzoic acid in the solid sample

Explanation:

The benzoic acid reacts with NaOH as follows:

C6H5COOH + NaOH → C6H5COONa + H2O

Where 1 mole of the acid reacts per mole of NaOH

The NaCl doesn't react with NaOH

To solve this question we must find the moles of NaOH added = Moles of benzoic acid. With the moles of the acid and its molar mass (C6H5COOH = 122.12g/mol) we can find the mass of the acid and its mass percentage:

a. Moles NaOH = Moles Benzoic acid:

24.78mL = 0.02478L * (0.150mol / L) = 0.003717 moles Benozic acid

Mass benzoic acid:

0.003717 moles Benozic acid * (122.12g / mol) = 0.4539g benozic acid

b. Mass percentage is:

0.4539g / 0.7529g * 100 = 60.29% of benzoic acid in the solid sample

Answer:

Option D. 230 J

Explanation:

We'll begin by calculating the temperature change of the iron. This can be obtained as follow:

Initial temperature (T₁) = 50 °C

Final temperature (T₂) = 75 °C

Change in temperature (ΔT) =?

ΔT = T₂ – T₁

ΔT = 75 – 50

ΔT = 25 °C

Thus, the temperature change of the iron is 25 °C.

Finally, we shall determine the amount of heat energy used. This can be obtained as follow:

Mass (M) = 20 g

Change in temperature (ΔT) = 25 °C

Specific heat capacity (C) = 0.46 J/gºC

Heat (Q) =?

Q = MCΔT

Q = 20 × 0.46 × 25

Q = 230 J

Thus, the amount of heat used was 230 J

Answer:

The minimum mass of ethylene glycol = 6.641 Kg

Explanation:

[tex]\Delta T_f= T_f-T_f'\\T_f'=T_f-\Delta T_f[/tex]

Where T_f = freezing point of pure solvent water, 0°C

T_f'= Freezing point of solvent after mixture

K_f = Freezing point depression constant = 1.86 °C/m

Moecular weight of ethylene glycol = 60 g/mol

Weight of ethylene glycol = 14.5 Kg= 14.5×10^3 g

molality of ethylene glycol

[tex]m = \frac{weight}{mol.wt} \times\frac{1000}{V}[/tex]

Substitute the values to calculate m

[tex]m = \frac{w}{60} \times\frac{1000}{14.5\times1000}[/tex]

by formula

[tex]0-(-14.2) =1.86\frac{w}{60} \times\frac{1000}{14.5\times1000}[/tex]

calculating we get w = 6641.93 g

Therefore, The minimum mass of ethylene glycol = 6.641 Kg