A food item that is left out of the refrigerator turns brown and forms bubbles and gas. What are the signs that this is a chemical reaction? Check all that apply. * 2 points Heat is produced Bubbles appear. The color changes. Heat is absorbed. A precipitate forms.

Answers

Answer 1

The formation of bubbles and the change in color of the food item are signs of a chemical reaction, indicating the production of gas and the creation of new substances.

When a food item left out of the refrigerator turns brown, forms bubbles, and releases gas, the signs that a chemical reaction has occurred include the production of gas (evidenced by bubbles) and a change in color. These are key indicators that the original substances have undergone a chemical change to form new substances with different properties. While heat can be absorbed or produced during a chemical reaction, the question does not specify that this occurred, and there is no mention of a precipitate being formed.


Related Questions

between sour soup,melting of candle wax,rusting, and burning which is not a chemical reaction

Answers

Sour soup is not a chemical reaction


Sour soup is not a chemical reaction.

In the formula for water (H2O), what does the subscript 2 indicate?

Answers

It tells you that each unit of this compound contains two atoms

the answer is actually "Two hydrogen atoms in the compound" >.>

What are the atomic number and mass number of this atom

Answers

No diagram is given therefore I cannot answer however, use this for reference.
The atomic mass of an atom would be the number of protons PLUS the number of neutrons. Because this atom shown has 6 protons and 6 neutrons, they add up to 12. In this case, the atomic mass of this atom is 12. Atomic number is the number of protons in an atom, in this case it is 6. The atomic number is 6.

which of these substance are likely to have a bitter taste antacod vi ger or anyacod toothpaste or orange jucoe and vinger or orange juice toothpaste

Answers

Answer : The correct option is, Antacid and toothpaste.

Explanation :

The property of an acid is that they are sour in taste and the property of base is that they are bitter in taste.

In the given question, vinegar, orange juice are the acids and antacids, toothpaste are the bases.

Therefore, the option Antacid and toothpaste are likely to have a bitter taste.


Which of the following is correctly abbreviated SI unit describing the mass of an object?

A) kg
B) mol
C) m
D) M

Answers

Which of the following is correctly abbreviated SI unit describing the mass of an object?

A) kg

A) kg is your answer

"Mass" is weight without gravity, and so the SI unit would also use the weight measurement. (You solve by dividing the force of gravity from the total weight to get mass.)

~

What salt is formed by the reaction of potassium hydroxide and hydrochloric acid?

Answers

Potassium hydroxide (KOH) is formed when Potassium forms ionic bonds with OH-ions while Potassium Oxide (K2O) is formed when potassium forms ionic bonds with the Oxide (O2-) ions. i.e. This reaction is a neutralization reaction and occurs when an acid (HCl) reacts with a base (KOH).

Answer: potassium chloride

Explanation:

Double displacement reaction is one which involves exchange of ions. Neutralization is a type of double displacement reaction in which an acid combines with a base to form salt and water, the reaction is called as neutralization reaction.

[tex]KOH+HCl\rightarrow KCl+H_2O[/tex]

Thus the salt formed is potassium chloride which has the chemical formula [tex]KCl[/tex].

A gas occupies volume of 30 milileters at 273 K if the temperature is increased to 364 k while the pressure remains constant what will be the volume of the gas

Answers

Answer:

40 mL

Step-by-step explanation:

The pressure is constant.

The only variables are volume and temperature, so we can use Charles’ Law.

V₁/T₁ = V₂/T₂     Multiply each side by T₂

V₂ = V₁ × T₂/T₁

V₁ = 30 mL; T₁ = 273 K  

V₂ = ?;         T₂ = 364 K

V₂ = 30 × 364/273

V₂ = 40 mL

AgI + Na2S Ag2S +NaI=

Answers

The equation needs to be balanced and written as,

[tex]2AgI+1 Na_{2} S[/tex]→[tex]1Ag_{2} S+2NaI[/tex]

Both side of compound should contain equal masses.

Which of the following best describes a metal? Brittle, shiny, and solid Brittle, dull, and low density Malleable, shiny, and able to conduct heat or electricity Malleable, dull, and solid, liquid, or gas at room temperature?

Answers

Answer : The correct option is, Malleable, shiny, and able to conduct heat or electricity.

Explanation:

Metals : Metals are the elements which can easily loose electrons and forms cations.

Properties of metals :

They are lustrous (shine).They are malleable and ductile (flexible).They conduct heat and electricity.The metallic oxides are basic in nature. They form cations in an aqueous solution.

Non-metals : Non-metals are the elements which can easily gain electrons and form an anion.

Properties of non-metals :

They are non-lustrous.They are brittle and hard in nature.They do not conduct heat and electricity.The non-metallic oxides are acidic in nature. They form anions in an aqueous solution.

Hence, from the given options the correct option for metal is, Malleable, shiny, and able to conduct heat or electricity.

Answer:

Malleable, shiny, and able to conduct heat or electricity

Hope this helps! :D

Explanation:

List the 3 ways carbon can enter the ocean?

Answers

Final answer:

Three ways carbon can enter the ocean are through running water, atmospheric dissolution, and decomposition of aquatic organisms.

Explanation:

Carbon can enter the ocean through three main ways:

Running water: Carbon is slowly dissolved in rocks by running water and eventually ends up in the ocean.Atmospheric dissolution: The top layer of ocean water dissolves some carbon dioxide out of the atmosphere.Decomposition of aquatic organisms: Carbon enters ocean water from the decomposition of aquatic organisms.

When molecules slow down, they expand.

A
True

B
False

Answers

False. <--- This is wrong I was thinking of atoms


Molecules do expand when they slowdown...


Hello.

The answer: A. True.

When mouecules slow down they can expend and this is how gas is made.

Have a nice day.

If an automobile travels at 30. m/s for 2 minutes, how far has the car traveled?

Answers

3600 miles! to get this answer you first need to know that  

60+60= 120  

then just times tht by 30 and you get 3600!

Final answer:

The car traveling at a constant speed of 30.0 m/s for 2 minutes covers a distance of 3600 meters.

Explanation:

To calculate the distance traveled by a car that moves at a constant speed, we can use the formula distance = speed × time. Given that the car travels at a constant speed of 30.0 m/s for 2 minutes, we first need to convert the time from minutes to seconds since the speed is given in meters per second.

There are 60 seconds in a minute, so 2 minutes equals 2 × 60 = 120 seconds.

Now, we can calculate the distance:

Distance = Speed × Time
Distance = 30.0 m/s × 120 s
Distance = 3600 meters

Therefore, the car has traveled a distance of 3600 meters.

Write a balanced equation for double replacement of KOH+ZnCl2

Answers

Answer :

Double replacement reaction : It is a type of reaction in which a positive cation and a negative anion of the reactants react to give a new compound as  a product.

[tex]AB+CD\rightarrow AD+CB[/tex]

In this, A and C are the cations and B and D are the anions.

When one mole of potassium hydroxide react with the one mole of zinc chloride to give one mole of zinc hydroxide and 2 moles of potassium chloride.

The balanced chemical reaction is,

[tex]KOH+ZnCl_2\rightarrow Zn(OH)_2+2KCl[/tex]

Is a microvilli is a tiny finger like projection that kills bacteria in the lymphatic system? true or false

Answers

Villi are tiny finger like projections present in the inner epithelial lining of the intestine. Each finger like villi is further divided into microvilli, which is the extension of plasma membrane of each epithelial cell of the villi. These villi and microvilli present on the inner surface of the intestine provide a greater surface area and this enhances the digestion and absorption of the nutrients.

Therefore, the correct answer is false as a microvilli is the tiny finger like projection of the inner epithelial cells of the small intestine that has absorptive functions.

in sexual reproduction, of each chromosome in a pair has the same genes, how is genetic variety possible?

Answers

This answer will depend on if you are speaking about asexual reproduction or not.

Variety is possible here because the the product genes are half from the mother and half from the father. So a child might have blue eyes from his mother, but red hair from his father, etc. Different genetic mutations are the initial cause of all differentiation between genes, which are passed down from each generation to the next through this same process.

In Asexual reproduction, all reproductions are essentially clones of the parent, and no genetic variation, other than mutations will occur.

Punnet Squares, they are charts to determine genetic variation by genotype and phenotype :)

What is the volume(in liters at stp) of 2.50 mil of carbon monoxide

Answers

The volume of one mole of substance is 22.4 L

To find the volume of 2.50 moles of carbon monoxide at STP, you multiply the moles by the molar volume at STP (22.4 L/mol), which gives you 56.0 liters.

To calculate the volume of carbon monoxide (CO) at standard temperature and pressure (STP), we should use Avogadro's Law. At STP, one mole of any gas occupies 22.4 liters. Given the amount of carbon monoxide in moles, we can determine the volume it would occupy at STP.

To find the volume:

Volume at STP (V) = Number of moles (n) x Molar volume at STP (Vm)

We know that:

[tex]n = 2.50\ moles\\ V_m = 22.4\ L/mol\ (volume\ occupied\ by\ one\ mole\ of\ gas\ at\ STP)[/tex]

So:

[tex]V = 2.50\ moles \times 22.4\ L/mol\\ V = 56.0\ liters[/tex]

This is the volume of 2.50 moles of carbon monoxide gas at standard temperature and pressure.

Hey can you please help me with this I really need y’all

Answers

#6 is the sec one,,,#7 is the first one,Nitrogen & gas....hope that helps

Determine the heat given off to the surroundings when 9.873 g of aluminum reacts according to the equation 2Al + Fe2O3 → Al2O3 + 2Fe, ΔH°rxn= -849.1 kJ/mol.

Answers

Answer : The heat given off to the surroundings will be, -155.38 KJ

Solution : Given,

[tex]\Delta H^o_{rxn}=-849.1KJ/mole[/tex]

Mass of aluminium = 9.873 g

Molar mass of aluminium = 27 g/mole

First we have to calculate the moles of aluminium.

[tex]\text{ Moles of Al}=\frac{\text{ Mass of Al}}{\text{ Molar mass of Al}}=\frac{9.873g}{27g/mole}=0.366moles[/tex]

The given balanced reaction is,

[tex]2Al+Fe_2O_3\rightarrow Al_2O_3+2Fe[/tex]

From the reaction, we conclude that

2 moles of aluminum releases heat energy = -849.1 KJ

0.366 moles of aluminium releases heat energy = [tex]\frac{-849.1KJ}{2moles}\times 0.366moles=-155.38KJ[/tex]

Therefore, the heat given off to the surroundings will be, -155.38 KJ

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) In a particular experiment, 4.00-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g.

Answers

6.69 g.

Explanation

Make sure the chemical equation is balanced:

[tex]6\; \text{Li}\; (s) + \text{N}_2 \; (g) \to 2\; \text{Li}_3\text{N}\; (s)[/tex]

Assuming that one mole of N₂ is consumed. How many grams of each reactant will that take? Refer to a periodic table for data on atomic mass.

6 × 6.94 = 41.64 grams of Li;1 × (2 × 14.01) = 28.02 grams of N₂.

4.00 grams of each reactant are available. How many moles of N₂ can they consume?

4.00 grams of Li will lead to up to 4.00 / 41.64 = 0.09606 moles of the reaction.4.00 grams of N₂ will lead to up to 4.00 / 28.02 = 0.1428 moles of the reaction.

However, only 0.09606 moles of the reaction is possible, since Li would have ran out before all 4.00 grams of N₂ are used up.

Each mole of the reaction makes 2 moles of Li₃N. 0.09606 moles of the reaction will produce 0.09606 × 2 × (3 × 6.94 + 14.01) = 6.69 grams of Li₃N.

iron plus lead (||)sulfate react forming iron (||) sulfate plus lead

Answers

Fe + PbSO4 -> FeSO4 + Pb

Final answer:

Fe(s) + PbSO4(s) = FeSO4(aq) + Pb(s)

Explanation:

The question involves a reaction where iron reacts with lead (II) sulfate, resulting in the formation of iron (II) sulfate and lead. This type of reaction is a single displacement reaction where a more reactive metal (iron) displaces a less reactive metal (lead) from its compound. To balance the reaction, we would write it as:

Fe(s) + PbSO4(s) = FeSO4(aq) + Pb(s)

Here, solid iron reacts with solid lead (II) sulfate to produce aqueous iron (II) sulfate and solid lead. This reaction is guided by the activity series, which predicts whether certain chemical reactions will occur based on the reactivity of the metals involved. In this case, since iron is more reactive than lead, it can displace lead from its sulfate compound.

What is true of a decomposition reaction? The reactants are usually a metal and a nonmetal. The reactants are generally two ionic compounds in an aqueous solution. The addition of energy in the form of heat or electricity is often required. Water is usually one of the reactants.

Answers

Answer

In a true decomposition reaction, the addition of energy in the form of heat or electricity is often required.

Explanation

A decomposition reaction is a chemical reaction that starts with single reactants to give new compounds as the products. These reaction requires a source of energy that could be light, heat  or electricity to facilitate the breaking-down of the chemical bonds.


Answer:

The addition of energy in the form of heat or electricity is often required.

what types of charge does a

Answers

protons have a positive charge
neutrons have no charge
electrons have a negative charge

A metal has higher reactivity than mag esoum where would the metal be on a periodic table

Answers

Answer is: below magnesium in group 2 or in group 1 (left from magnesium).

Reactivity series is an empirical progression of a series of metals, arranged by their reactivity from highest to lowest (alkaline metals have highest reactivity and Noble metals lowest reactivity).

This series are used to summarize information about the reactions of metals with acids or water, double displacement reactions (more reactive metals displace metals with lower reactivity) and the extraction of metals from their ores.

Sodium and potassium (group 1 - alkaline metal) are more reactive than magnesium.

Strontium and barium (group 2 in periodic table) are higher in this group from magnesium. Strontium is stronger reducing agent than magnesium, gives electrons easier.

is P2I4 or Diphosphorus tetraiodide covalent or ionic?

Answers

Diphosphorus tetraiodide  is a covalent compound.

It has low melting point as compared to ionic compounds

It is a rare compound where the oxidation state of Phosphorous is +2.

It is also termed as subhalide of phosphorous.

Answer: covalent bond.

Explanation:

A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.

An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element and the element which accepts the electrons is known as electronegative element. This bond is formed between a metal and an non-metal.

As [tex]P_2I_4[/tex] or Diphosphorus tetraiodide is made up of phosphorous and iodine which are both non metals , it is a covalent bond.

explain why subscripts cannot change when balancing a chemical equation

Answers

not be changed to balance an equationSubscripts are part of the chemical formula for reactants or products and can

Changing a subscript changes the substance represented by the formula

Subscripts are the identity of the element (the number of atoms) whereas coefficients are the number of molecules of the element.

If you change the subscript, you change the number of atoms an element has. This changes the entire element since each element in the periodic table have different atomic numbers.

how many individual atoms make up one unit of aluminum chloride, ALCL3?

Answers

4 atoms make up aluminium chloride: 1 aluminum atom and 3 chlorine atoms

Question: Draw a valid Lewis structure for the molecule CH3NO in which there are no nonzero formal charges on any of the atoms. This structure should not include any bonds between N and O.

what do you do with the oxygen?

Answers

The mentioned molecule with formula, CH₃NO where no bond is found between N and O can be depicted as formamide is shown in the attachment below.  

The formal charges = Number of valence electrons for the atom (V) - the number of electrons in lone pairs (N) - 1/2 (number of electrons in bond pairs, B)

FC = V - N - B/2

Thus, there is a need to calculate valence electrons, electrons in lone pairs, and the number of electrons in bond pairs for each atom in the mentioned molecule.  

V or valence electrons on C = 4e, on H = 1e, on N = 5e, and on O = 6e.  

N or electrons in lone pairs on C = 0e, on H = 0e, on N = 2e, and on O = 4e.  

B or number of electrons in bond pairs for C = 8e, for H = 2e, for N = 6e, and for O = 4e.  

Thus, the formal charges for each will be,  

C = 4 - 0 - (8/2) = 0

H = 1 - 0 - (2/2) = 0

N = 5 - 2 - (6/2) = 0

O = 6 - 4 - (4/2) = 0

Lewis dot structure for the given molecule is given in the attachment below:


Answer :  The Lewis-dot structure of [tex]CH_3NO[/tex] is shown below.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The given molecule is, [tex]CH_3NO[/tex]

As we know that carbon has '4' valence electrons, hydrogen has '1' valence electron, nitrogen has '5' valence electrons and oxygen has '6' valence electrons.

Therefore, the total number of valence electrons in [tex]CH_3NO[/tex] = 4 + 3(1) + 5 + 6 = 18

According to Lewis-dot structure, there are 12 number of bonding electrons and 6 number of non-bonding electrons.

Now we have to determine the formal charge for each atom.

Formula for formal charge :

[tex]\text{Formal charge}=\text{Valence electrons}-\text{Non-bonding electrons}-\frac{\text{Bonding electrons}}{2}[/tex]

[tex]\text{Formal charge on O}=6-4-\frac{4}{2}=0[/tex]

[tex]\text{Formal charge on C}=4-0-\frac{8}{2}=0[/tex]

[tex]\text{Formal charge on N}=5-2-\frac{6}{2}=0[/tex]

[tex]\text{Formal charge on }H_1=1-0-\frac{2}{2}=0[/tex]

[tex]\text{Formal charge on }H_2=1-0-\frac{2}{2}=0[/tex]

[tex]\text{Formal charge on }H_3=1-0-\frac{2}{2}=0[/tex]

Hence, the Lewis-dot structure of [tex]CH_3NO[/tex] is shown below.

For a 0.50 molal solution of sucrose in water, calculate the freezing point and the boiling point of the solution.

Answers

Answer:

-0.93 °C; 100.26 °C  

Step-by-step explanation:

(a) Freezing point depression

The formula for the freezing point depression ΔT_f is

ΔT_f = iKf·b

i is the van’t Hoff factor: the number of moles of particles you get from a solute.

For sucrose,

    Sucrose (s)   ⟶   sucrose (aq)

1 mole sucrose ⟶ 1 mol particles     i = 1

ΔT_f = 1 × 1.86 × 0.50

ΔT_f = 0.93 °C

 T_f = T_f° - ΔT_f  

 T_f = 0.00 – 0.93  

 T_f = -0.93 °C

(b) Boiling point elevation

The formula for the boiling point elevation ΔTb is

ΔTb = iKb·b

ΔTb = 1 × 0.512 × 0.50

ΔTb = 0.256 °C

 Tb = Tb° + ΔTb  

 Tb = 100.00 + 0.256  

 Tb = 100.26 °C

Answer:

Explanation:

1. If the Kf = 1.86 ºC / m for water, what is the freezing point depression for the sucrose solution?

ΔT = iKf m

i=1 for sucrose

Kf = 1.86 ºC / m

m = 0.50

ΔTf = 1.86 x 0.50 = 0.93 ºC

2. If the Kb = 0.512 ºC / m for water, what is the boiling point elevation for the sucrose solution?

ΔT = i Kb m

i=1 for sucrose

Kf = 0.512 ºC / m

m = 0.50

ΔTf = 0.512 x 0.50 = 0.26 ºC

A substance which produces hydroxide ions when placed in water is a(n) _____.
A:dehydrate
B:base
C:solvent

99 points to whoever best answer.

Answers

The answer you're looking for is B:base

The base is disestablished in the water, and the molecules form into ions and produces OH- ions.


Like your profile picture


Hope this helped:D


Question: A substance which produces hydroxide ions when placed in water is a _____.

Answer: base

Explanation:  a substance that contains hydrogen causes to produce hydrogen ions

question answered by

(jacemorris04)

How do properties, such as Density, help us to classify and identify matter?

Answers

Density can be defined in terms of the mass of a substance present in a certain volume.

i.e. Density = Mass/ volume

It helps classify and identify matter due to the following reasons:

1) Density is an intensive property. For a given substance the density will remain the same irrespective of the amount in which it is present.

For example: The density of Aluminum (Al) = 2.7 g/cm3. This value is a constant at a certain temperature and pressure. Therefore, the density will remain the same for 1 kilogram or 1 mg of Al

2) Different elements/compounds have different values of densities which is characteristic of that substance

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