help me please just w number 2&3

Answer:

68.6 °C

Explanation:

From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'

Q = Q'

Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g

Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown

So, mL = m'c(θ₂ - θ₁)

θ₂ - θ₁ = mL/m'c

θ₂ = mL/m'c + θ₁

substituting the values of the variables into the equation, we have

θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C

θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C

θ₂ = 43.56 °C + 25 °C

θ₂ = 68.56 °C

θ₂ ≅ 68.6 °C

So, the final temperature (in °C) of the metal block is 68.6 °C.

The final temperature of the metal block is 74.97°C

The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.

From the parameters given:

The number of moles of acetone is:

[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]

= 0.0573 mol

At standard conditions, the heat of vaporization of acetone is:

[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]

Given that:

The specific heat of the aluminum is = 0.903 J/g° C

The heat energy can be computed as:

q = msΔT

q = 41 g × 0.903 J/g° C × (x - 25°C)

Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.

i.e.

[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]

[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]

[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]

[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]

x = 74.97 °C

Learn more about specific heat here:

https://brainly.com/question/1430612

Answer:

159571 lb or cubic feet

Explanation:

Answer: [tex]Co+2Na_2S\rightarrow 4Na+CoS_2[/tex]

Explanation:

According to law of conservation of mass, mass can neither be created nor be destroyed. The atoms on the reactant side must be equal to the number of atoms on the product side so that the mass remains the same on reactant and product side. Thus the reactions are balanced.

Single displacement reaction is one where a more reactive element replaces the lesser reactive one.

The balanced chemical reaction will be:

[tex]Co+2Na_2S\rightarrow 4Na+CoS_2[/tex]

Answer:

I think 5

Explanation:

Answer:

Electrical and magnetic

You exert a gravitational force on the pupil and the pupil exerts an equal gravitational force on you. ... The size of the gravitational force depends on the mass of the objects involved. The greater the mass, the greater the gravitational force.

Explanation:

Answer:

As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.

Answer:

4 mol

Explanation:

Given data:

Number of atoms of He = 2.4 × 10²⁴ atoms

Number of moles of He = ?

Solution:

Avogadro number:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ atoms

2.4 × 10²⁴ atoms × 1mol / 6.022 × 10²³ atoms

0.398× 10¹ mol

3.98 mol ≅ 4 mol

Answer:

detail is given below.

Explanation:

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

For example:

In given photosynthesis reaction:

6CO₂ + 6H₂O  → C₆H₁₂O₆ + 6O₂

The given equation is balanced chemical equation of photosynthesis. There are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.

If equation is not balanced,

CO₂ + H₂O  → C₆H₁₂O₆ + O₂

It can not follow the law of conservation of mass because mass is not equal on both side of equation.

Answer:

Percentage of O = 56.1 %

Percentage of Al =15.8%

Percentage of S = 28.1 %

Explanation:

Given compound Al₂(SO₄)₃

Molar mass of compound:

27×2 + 32×3 + 16×12 = 342 g/mol

Percentage of Al = ( Mass of Al / Total mass ) × 100

Percentage of Al = 54 /342 × 100

Percentage of Al =15.8%

Percentage of S = ( Mass of S / Total mass ) × 100

Percentage of S = 96 /342 × 100

Percentage of S = 28.1 %

Percentage of O = ( Mass of O / Total mass ) × 100

Percentage of O = 192 /342 × 100

Percentage of O = 56.1 %

Answer:

Its in the Explanation

Explanation:

Here's what I got.

Aluminium-27 is an isotope of aluminium characterized by the fact that is has a mass number equal to  

27

.

Now, an atom's mass number tells you the total number of protons and of neutrons that atom has in its nucleus. Since you're dealing with an isotope of aluminum, it follows that this atom must have the exact same number of protons in its nucleus.

The number of protons an atom has in its nucleus is given by the atomic number. A quick looks in the periodic table will show that aluminum has an atomic number equal to  

13

.

This means that any atom that is an isotope of aluminum will have  

13

protons in its nucleus.

Since you're dealing with a neutral atom, the number of electrons that surround the nucleus must be equal to the number of protons found in the nucleus.

Therefore, the aluminium-27 isotope will have  

13

electrons surrounding its nucleus.

Finally, use the known mass number to determine how many neutrons you have

mass number

=

no. of protons

+

no. of neutrons

no. of neutrons = 27 − 13 = 14

Your welcome :)

Answer:

fire

Explanation:

Answer:

ants if you splash a ant with sum water that shít is dead

Answer:

Mass = 917.4 g

Explanation:

Given data:

Number of molecules = 3.00 ×10²⁴ molecules

Mass in gram = ?

Solution:

1 mole contain 6.022 × 10²³ molecules

3.00 ×10²⁴ molecules × 1 mol /  6.022 × 10²³ molecules

0.5×10¹ mol

5 mol

Mass in gram:

Mass = number of moles  × molar mass

Mass = 5 mol  × 183.48 g/mol

Mass = 917.4 g

Answer:

Between carbon and silicon, silicon element has the strongest attraction between its nucleus and its valence electrons.

because silicon's nucleus is bigger than carbon.silicon loses electrons easily than carbon.

Answer:

D.) This atom has an atomic number of 50

Explanation:

A is wrong because we determine the type of atom by their number of protons, not the number of neutrons. This makes the atom Tin (Sn).

B is wrong because both protons and neutrons contribute to the weight of an atom, not just neutrons

C is wrong because the correct name for this isotope would be tin-119, which is calculated by adding the protons and neutrons

D is correct because isotopes of the same element always share the same atomic number

Answer:

Explanation:

The major regulation, regulatory, and communicating system in the body is the nervous system. It is the foundation of all mental operation, including thinking, learning, and memory. The nervous system, along with the endocrine system, is responsible for controlling and sustaining homeostasis.

Answer: [tex]KClO_3[/tex] is the limiting reactant in the given reaction.

Explanation:

Limiting reagent is defined as the chemical specie which gets totally consumed in the reaction and the formation of product is dependent on this reagent.

We are given:

Moles of [tex]P_4[/tex] = 30 moles

Moles of [tex]KClO_3[/tex] = 86 moles

The given chemical equation follows:

[tex]10KCIO_3+3P_4\rightarrow 3P_4O_{10}+10KCI[/tex]

By Stoichiometry of the reaction:

If 10 moles of [tex]KClO_3[/tex] reacts with 3 moles of [tex]P_4[/tex]

Then, 86 moles of [tex]KClO_3[/tex] will react with = [tex]\frac{3}{10}\times 86=25.8moles[/tex] of [tex]P_4[/tex]

As, given amount of [tex]P_4[/tex] is more than the required amount. So, it is considered as an excess reagent.

Therefore, [tex]KClO_3[/tex] is considered as a limiting reactant because it limits the formation of product.

Answer:

Buffalo and Watertown.

Explanation:

This is correct as the Interior lowlands are located ib the US. These are correct as the others are in the US but aren't located anywhere near the Interior Lowlands.

Answer:

by focal length of the eyepiece.

Explanation:

hope it helps!!plz mark as brainleist.

Answer:

3.79 x 10²⁴atoms

Explanation:

Given parameters:

Number moles of lead  = 6.3moles

Unknown:

Number of atoms  = ?

Solution:

To solve this problem,

              1 mole of a substance contains  6.02 x 10²³ atoms

            6.3 mole of Pb  will contain 6.3  x 6.02 x 10²³ = 3.79 x 10²⁴atoms

Answer:

I'd say about 8?

Explanation:

if you wanna make them huge make about 6

Answer:

0.55g/L

Explanation:

Given parameters;

Mass of salt  = 55g

Volume of water  = 100L

Unknown:

g/L concentration  = ?

Solution:

To solve this problem, we must understand that concentration is the amount of solute per solution

 g/L concentration  = [tex]\frac{55}{100}[/tex]   = 0.55g/L

Answer:

I think it would be Yellow

Answer:

Answer at the bottom

Explanation:

A Be

B Li

C Mg

D Nahe answered their bottom

Explanation:

In animal cells, vacuoles are small and help sequester waste products. In plant cells, vacuoles help maintain water balance. Therefore the answer should be B. For Storage

Hope this helps!

Please mark brainliest!

Answer:

it would become darker. there would be a higher level of water pressure. and there would be less animals, or different alimals.

Answer:

1. Broadly, there are three different methods for how electricity is generated in the United States. They include; Fossil fuels, Nuclear energy, and Renewable energy sources.

2. Fossil fuels, are used the most, with Natural gas topping the list by 38%.

3. More should be invested into renewable gas. It is a clean source of energy and investing in it would bring about a cleaner and safer environment.

Explanation:

Fossil fuels arise from plants and animals that have been long dead and can can now be converted to sources of energy. Examples include; coal natural gas, crude oil. etc.  

Nuclear energy arises from the fission of uranium atoms, nuclear decay, and nuclear fusion. They are safe since green house gases are not emitted. Thermal energy can be generated as the byproduct of these reactions.

Renewable sources of energy are generated from natural sources which are always available. Examples are; sun, wind, biomass, water, and geothermal sources,

Answer:

Metals in general have they chemical property of reacting with an acid. Zinc reacts with hydrochloric acid to produce hydrogen gas. This is a chemical property. Chemical change results in one or more substances of entirely different composition from the original substances.

Metal reacts with acid is a chemical property.

Metals react with acids which causes the production of salt and hydrogen gas is released. This is a chemical property because the reactions of reactant produces new type of products which is totally change from the parent material or reactants. The  chemical property is refers to change of one type of matter into another type so we can conclude that reaction of metals with acid is a chemical property.

Learn more: https://brainly.com/question/20677720