Laura has three beakers. Each contains 200 cm3 of a colourless liquid. Suggest how Laura could nd out which beakers contain pure water, and which contain solutions.

Answer:

Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage. Most high quality microscopes include an Abbe condenser with an iris diaphragm. Combined, they control both the focus and quantity of light applied to the specimen.

Answer:

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

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

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Answer:

fire

Explanation:

Answer:

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

Answer:

Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.

Explanation:

Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.

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:

H₂O₂

Explanation:

Hydrogen peroxide is a typical example of a compound molecule. A compound is made up of one or more atoms that are combined together in a definite grouping.

The properties of a compound is different from those of the elements that combines to from them.

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

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

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Answer:

d = 8.96 g/cm³

Explanation:

Given data:

Volume of sample = 10.0 cm³

Mass of copper = 89.6 g

Density of copper = ?

Solution:

Formula:

d = m/v

d = density

m = mass

v = volume

by putting values,

d = 89.6 g/ 10.0 cm³

d = 8.96 g/cm³

Answer:

159571 lb or cubic feet

Explanation:

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:

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: [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:

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:

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:

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Answer:

I'd say about 8?

Explanation:

if you wanna make them huge make about 6

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:

Sound is vibrations that travel through a medium, and which are then converted into electrical signals by our brain so that we interpret them as a noise that we hear. These vibrations consist of particles colliding with each other (this is why sound cannot travel through space; there are no particles). At warmer temperatures, the particles that make up air will move faster, so these collisions will happen more frequently. Therefore the vibrations occur more quickly, so sound travels faster and reaches our ears in a shorter amount of time.

The speed of sound can travel faster in hot air than it can in cold air. This is because the molecules of air can move even faster and the vibrations of the sound wave can transmit faster. Sound is a type of mechanical wave, meaning that it requires a medium to transmit energy. Mediums are any substance that has mass and takes up space, from the air in the room to the metal atoms in an iron fence.

Explanation:

hope that helps :)

Answer:

Sound travels faster in a warm room because temperature affects the speed of a wave. In a warm room, the particles of air move faster and have higher chances of bumping into each other, which then increases the instances of energy transfer.

Explanation:

just trust me cuz

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:

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.

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Answer:

0.4 km/h  velocity is also the direction their going, in this case the person, that I'll name billy bob joe, is going in so yeh

Explanation:

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Answer:

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

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:

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