A teacher brings in a cup of iced water and asks students to discuss if the system is exothermic or endothermic . Aida states the system is exothermic , while Alexander states the system is endothermic .

Answer:

Give an example of each of the following chemical changes.

(a) A photochemical reaction involving

(i) silver salt

(ii) water

(b) A reaction involving

(i) blue solution

(ii) formation of dirty green precipitate

(c) Two gases combine to form white solid.

(d) A reaction where colour change is noticed.​

Explanation:

a) A photochemical reaction involving  silver salt is used in black and white photography.

AgCl breaks down and converts into Ag during this photochemical reaction.

(ii) Photochemicalreaction involving water takes place in plants during the photosynthesis process.

Plants prepare food(carbohydrate) by using sunlight water and CO2 gas.

(b) A reaction involving

(i) blue solution:

For example reaction of copper sulfate solution with an iron nail.

When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.

(ii) Reaction of ferrous sulfate with NaOH forms a dirty green precipitate of ferrous hydroxide.

(C) Two gases combine and form a white solid:

For example when HCl gas reacts with ammonia gas, then a white solid of ammonium chloride will be formed.

(d)  A reaction where the color change is noticed.:

When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.

Answer:

C

Explanation:

Q and R forms a nitrate. When dissolved in water it will form a solution with a pH greater than 7 because the solution is alkaline.

According to VSEPR theory, geometry of water molecule is bent.

Learn more:

brainly.com/question/12775505

Answer:

It is tetrahedral because there are two bonded pairs and two lone pairs around oxygen.

Explanation:

Took it

Answer:

Gain energy, move less, become closer together

Answer: sorry its lagging i hope this help fore 18.. =D

Explanation:

n,s is repeating the cycle of the inside

Answer/Explanation:

18, a,

I believe the n, and s represents North, South, or just the way the arrows are rotating repeatedly.

18, b,

The phenomenon re-occurring shows the alignment of magnetic dipoles with in a magnet, like inside. The arrows show a direction in the line with an external magnetic field in a way that it can produce its own magnetic fields that seem to travel from North to the South.

18, c,

Incorrect. Refrigerator magnets have multiple layers of magnification, they use opposite polarities to stay this way. If he puts the magnet sideways it may stick to the fridge

~ LadyBrain

Answer:

A. Berryllium is a paramagnetic

Answer:

0.1125  mol/L

Explanation:

application fomula:

C1V1=C2V2

C1 is concentration of Ba(OH)2

V1 is volume of Ba(OH)2

C2 is concentration of HCl

V2 is volume of HCl

Answer:+5

Explanation: A P3X

Answer:

yes and yes and yes and absolutely yes. Yes do it

Answer:

Yes.

The nuclear equation {226/88 Ra → 222/26 Rn + 4/2 He} is balanced. As we know that an alpha particle is identical to a helium atom. This implies that if an alpha particle is eliminated from an atom's nucleus, an atomic number of 2 and a mass number of 4 is lost.

Therefore, the equation will be reduced to:

226 - 4 = 222

88 - 2 = 86

Hence, the equation is balanced.

Explanation:

Answer:

yes

Explanation:

s]imple yes

Answer:

A. Carbon, Hydrogen, Nitrogen, and Oxygen

B. 12(14) + 1(18) +12(2)+16(5)= 294.20g

C. 7.35/294.3=0.0250mol

D. 5.88g/294.3=0.01997961264 × 6.02 × 10^2= 12.028

Explanation:

Answer:

For a: The balanced equation is [tex]2S(s)+3O_2(g)\rightarrow 2SO_3(g)[/tex]

For c: The balanced equation is [tex]2NaOH(s)+H_2SO_4(aq)\rightarrow Na_2SO_4(aq)+2H_2O(l)[/tex]

Explanation:

A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.

The given unbalanced equation follows:

[tex]S(s)+O_2(g)\rightarrow SO_3(g)[/tex]

To balance the equation, we must balance the atoms by adding 2 infront of both [tex]S(s)[/tex] and [tex]SO_3[/tex] and 3 in front of [tex]O_2[/tex]

For the balanced chemical equation:

[tex]2S(s)+3O_2(g)\rightarrow 2SO_3(g)[/tex]

The given balanced equation follows:

[tex]2Al(s)+3Cl_2(g)\rightarrow 2AlCl_3(s)[/tex]

The given equation is already balanced.

The given unbalanced equation follows:

[tex]2NaOH(s)+H_2SO_4(aq)\rightarrow Na_2SO_4(aq)+H_2O(l)[/tex]

To balance the equation, we must balance the atoms by adding 2 infront of [tex]H_2O(l)[/tex]

For the balanced chemical equation:

[tex]2NaOH(s)+H_2SO_4(aq)\rightarrow Na_2SO_4(aq)+2H_2O(l)[/tex]

The given balanced equation follows:

[tex]C_3H_8(g)+5O_2(g)\rightarrow 3CO_2(g)+4H_2O(g)[/tex]

The given equation is already balanced.

Answer:

The study of the interaction of electrical and magnetic fields, and their interaction with matter, is called Electromagnetism

Answer: The given compounds are arranged in order of increasing entropy (S) as [tex]CH_{3}OH(s) < CH_{3}OH(l) < CH_{3}CH_{2}OH < CH_{3}OH(g)[/tex]

Explanation:

The degree of randomness present in a substance is called entropy.

This means that more is the number of molecules weakly held together and rapidly moving from one place to another more will be its entropy.

In solids, the molecules are held together strongly with each other. So, they will have least entropy.

In liquids, the molecules are a little loosely held together. So, they have more entropy than a solid substance.

In gases, the molecules are held by weak forces due to which they move rapidly from one place to another. Hence, gases have high entropy as compared to solids and liquids.

Also, more is the molecular mass of a gas less will be its rate of effusion. Hence, less will be its entropy.

[tex]Rate of effusion \propto \frac{1}{\sqrt{M}}[/tex]

where,

M = molecular mass

Thus, we can conclude that given compounds are arranged in order of increasing entropy (S) as [tex]CH_{3}OH(s) < CH_{3}OH(l) < CH_{3}CH_{2}OH < CH_{3}OH(g)[/tex]

Answer:

a.) open spaces in waters solid structure makes its solid state less dense than its liquid state.

Answer: It is a.) open spaces in waters solid structure makes its solid state less dense than its liquid state.

Explanation: This is because the solid state of water is less dense than its liquid state due to free spaces in its solid structure.

Answer:

43.8%

Explanation:

Find the sum of the relative atomic mass of all the elements constituting the compound, which is known as the relative formula mass;

[tex]M_{r} = Relative \ formula \ mass \\\\M_{r} \ of \ ZnSO_{4} = 65.4 + 32.1 + 4(16) \\\\M_{r} \ of \ ZnSO_{4} = 97.5 + 64 \\\\M_{r} \ of \ ZnSO_{4} = 161.5 \\\\M_{r} \ of \ H_{2}O = 18 \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 161.5 + 7(18) \\\\M_{r} \ of \ ZnSO_{4}.7H_{2}O = 287.5[/tex]

Then, divide the relative formula mass of all the water by that of the whole compound

w = % water

[tex]w = \frac{7(18)}{287.5} * 100 \\\\w = 0.43826... * 100\\\\w = 43.826...[/tex]

w = 43.8%

Answer:

See explanation

Explanation:

Let the equation of dissolution be;

AB2(s) ⇄A(aq) + 2S

Hence;

Ksp = [A] [2s]^2

Let the concentration of the species be s

Ksp= s × (2s)^2

Ksp= 4s^3

Since s= 5mol/dm^3

Ksp = 4(5mol/dm^3)^3

Ksp = 500 mol^2dm^-6

Answer:

I believe it's a.

Explanation:

Answerquit

Explanation:snns

Answer:

Malleability describes the property of a metal's ability to be distorted below compression. It is a physical property of metals by which they can be hammered, shaped and rolled into a very thin sheet without rupturing. A malleable fabric could be planate by blow or rolling.

Explanation:

Ductility is the property of a solid, like a metal, to deform under a tensile stress (force). So if you pull on two ends of a metal wire or bar, and it “stretches” you have a ductile substance. Though I must caution that you don't confuse the definition of ductile to mean elastic. They are not synonyms. It is the opposite of brittle. When a ductile item breaks, it is after necking, where the diameter of the wire in question reduces as the length elongated. A brittle, or non-ductile material simple tears apart in a sharp and quick fashion with little to no visible necking taking place.

sonorous: producing sound (as when struck)

Answer: Can i see the question

Explanation:

Answer: The final temperature will be [tex]23^oC[/tex]

Explanation:

Calculating the heat released or absorbed for the process:

[tex]q=m\times C\times (T_2-T_1)[/tex]

In a system, the total amount of heat released is equal to the total amount of heat absorbed.

[tex]q_1=-q_2[/tex]

    OR

[tex]m_1\times C_1\times (T_f-T_1)=-m_2\times C_2\times (T_f-T_2)[/tex]           ......(1)

where,

[tex]C_1[/tex] = specific heat of aluminium = [tex]0.21 Cal/g^oC[/tex]

[tex]C_2[/tex] = heat capacity of water = [tex]1Cal/g^oC[/tex]

[tex]m_1[/tex] = mass of aluminium = 30. g

[tex]m_2[/tex] = mass of water = 50. g

[tex]T_f[/tex] = final temperature of the system = ?

[tex]T_1[/tex] = initial temperature of aluminium = [tex]40.^oC[/tex]

[tex]T_2[/tex] = initial temperature of the water = [tex]21.^oC[/tex]

Putting values in equation 1, we get:

[tex]30\times 0.21\times (T_f-40)=-50\times 1\times (T_f-21)\\\\56.3T_f=1302\\\\T_f=\frac{1302}{56.3}=23.13^oC=23^oC[/tex]

Hence, the final temperature will be [tex]23^oC[/tex]

Answer: The mass of [tex]FeO[/tex] required is 14.37 g

Explanation:

Molarity is calculated by using the equation:

[tex]\text{Molarity}=\frac{\text{Moles}}{\text{Volume}}[/tex] ......(1)

We are given:  

Molarity of iron (II) sulfate = 1 M

Volume of solution = 200 mL = 0.200 L (Conversion factor: 1 L = 1000 mL)

Putting values in equation 1, we get:

[tex]\text{Moles of }FeSO_4=(1mol/L\times 0.200L)=0.200mol[/tex]

The chemical equation for the reaction of FeO with sulfuric acid follows:

[tex]FeO+H_2SO_4\rightarrow FeSO_4+H_2O[/tex]

By stoichiometry of the reaction:

If 1 mole of iron (II) sulfate is produced by 1 mole of FeO

So, 0.200 moles of iron (II) sulfate will produce = [tex]\frac{1}{1}\times 0.200=0.200mol[/tex] of FeO

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

We know, molar mass of [tex]FeO[/tex] = 71.84 g/mol

Putting values in above equation, we get:

[tex]\text{Mass of }FeO=(0.200mol\times 71.84g/mol)=14.37g[/tex]

Hence, the mass of [tex]FeO[/tex] required is 14.37 g

Answer:

Copper; Symbol is Cu

Protons = 29

Electrons = 29

Mass number = Protons + Neutrons

•°• Protons = Mass number - Neutrons

= (65-36)

= 29

Electrons is equal to the number of protons in a nucleus.

Answer:

a solute

Explanation:

the answer is a solute

Answer:

2NaOH + 2Al +2H2O = 2NaAlO2 +3H

Explanation:

Aluminum is an amphoteric element it reacts with both bases and acids to form a salt and hydrogen gas.The reaction is highly exothermic.

Answer:

Grand Tourer  Injection

Answer:

11.56

Explanation:

Answer:

A simple answer: Carnivores don't eat plants only flesh. So they would not need soil. But it would be hard for Carnivores to get energy because they get energy indirectly from the animals (herbivores) that they eat. How do they get the energy from a herbivore you might ask. Herbivores eat only plants and that gives the herbivore the plant's energy; but if the herbivore gets eaten, it is indirectly transferred into the Carnivore. Hope this helped!!

Carnivore = only feeds on flesh

Herbivore = eats only plants

Omnivore = eats plants and animals/flesh

Answer:b

Explanation:

I searched it