A physical change :_______
a) occurs when water is evaporated.
b) occurs when glucose is converted into energy within your cells.
c) occurs when sugar is heated into caramel
d) occurs when iron rusts.

Answer:

if it is pure, the substances is either an element or a compound. if a substance is not chemically pure, it is either a heterogeneous mixture or a homogeneous mixture. if its composition is uniform throughout, it is a homogeneous.

Answer:

[Na₂CO₃] = 0.15 M

Explanation:

Molarity is a type of concentration.

It is useful for solutions, to say how many moles of solute are contained in 1L of solution.

We can also say, that molarity are the mmoles of solute in 1 mL of solution.

In this case, our solute is the Na₂CO₃.

We convert mass to moles: 0.79 g . 1 mol / 106g = 7.45×10⁻³ moles

We convert moles to mmoles:  7.45×10⁻³ mol . 1000 mmol / 1mol = 7.45 mmol

M = mmol / mL

M = 7.45 mmol / 50 mL = 0.15 M

Option A is the right answer.

Answer:

To convert 100.0 g of water at 20.0 °C to steam at 100.0 °C requires 259.5 kJ of energy. Let me know if this helped?

Answer:

Liquid: 38.7 g x 1 ml/0.865 g = ml of liquid

Vol of solid = 80.0 ml - ml of liquid

mass of solid = vol of solid x 2.75 g/ml

(100. g)

Explanation:

you can use this as a eg for this question

1 mole KOH give 1 mole KCl

so 12.5 will give 12.5 mole of KCl

we know that 1 mole of kcl is equal to 74 grams

so 12.5 mole have

12.5 × 74= 926 grams

Answer:

Compound X has the formula C8H14.

X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethyl cyclohexane. Treatment of X with ozone followed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?

Explanation:

The degree of unsaturation in the given molecule C8H14 is:

DU=(Cn+1)-Hn/2-Xn/2+Nn/2

where,

Cn=number of carbon atoms

Hn=number of hydrogen atoms

Xn=number of halogen atoms

Nn=number of nitrogen atoms

C8H14:

DU=(8+1)-14/2

=>DU=9-7 =2

Hence, the given molecule will have either two double bonds or one double bond and one ring or two rings.

X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethylcyclohexane.

This indicates that the molecule X has one double bond and one ring that is cyclohexane ring.

Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O).

So, the molecule has a ring and double bond CH2.

Based on the given data the structure of compound X is shown below:

The reaction sequence is shown below:

Answer: The given chemical reaction can be classified as synthesis and exothermic.

Explanation:

A synthesis reaction is defined as the reaction where two small chemical species combine in their elemental state to form a single large chemical species.

Exothermic reactions are defined as the reactions in which heat is released by the reaction. The heat is written on the product side of the reaction.

For the given chemical reaction:

[tex]Mg(s)+O_2(g)\rightarrow MgO(s)+\text{heat}[/tex]

The above chemical reaction is a type of synthesis and exothermic as two substances in their elemental state are combining. Also, heat is getting released in the reaction.

Hence, the given chemical reaction can be classified as synthesis and exothermic.

An atom consists of three sub atomic particles which are protons, neutrons, and electrons. ... This nucleus is surrounded by the electrons as electrons revolve around the nucleus. Thus, we can conclude that out of the given options, a core of protons and neutrons surrounded by electrons best describes an atom.

and y'all still In school?

Answer:

5-Ethyl3-Methyloctane

Explanation:

Step in the naming of organic compound

Step 1: Take the longest continous carbon chain as the root hydrocarbon and name it according to the number of carbon atoms it contains, adding appropriate suffix to indicate the principal substituent group

Step 2:  Number the carbon atoms in the root hydrocarbons from the end which give the lowest number to the suffix, and then the prefix

Step 3:  Indicate other substituents by prefixes proceed by numbers to show their positions on the carbon chain

Applying the step above,

The longest carbon chain is  8, and the fuctional group is the single chain (alkane),

5-Ethyl3-Methyl,octane

Answer:

Explanation:

Bromination of allylic compounds occurs when hydrogen atoms from neighboring double bonds are replaced. As a result, there are four (4) potential bromination products, as seen in the figure below.

NBS, also known as N-Bromo succinimide, is employed as a replacement for Br2 in certain instances. The benefit of NBS is that it produces a reduced level concentration for Br2, which means that bromination of the double bond isn't competitive. As soon as Br2 has been produced, the reaction continues in the same way as the remaining free-radical halogenation reactions.

Answer:

Explanation:

[tex]E=h\nu=6.62606957 *10^{-34}\frac{Kg~m^2}{s}4.78*10^{14}\frac{1}{s}=316.7261*10^{-21}J[/tex]

Answer:

25%

Explanation:

Cystic fibrosis is a recessive allele, meaning that the child must be aa to suffer the symptoms. Only 1/4 of the paired alleles is aa, so the probability of getting cystic fibrosis would be 25%.

Answer:

the heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C). 1. See answer.

Answer:

Total number of ATP molecules generated from a 32-carbon fatty acid = 206 ATP molecules

Explanation:

A 32 carbon fatty acid which undergoes complete beta-oxidation assuming that the fatty acid is fully saturated will pass through the beta-oxidation cycle 14 times to produce the following:

15 molecules of acetylCoA, 14 molecules of FADH₂, and 14 molecules of NADH.

Each of the 15 acetylCoA molecules can be further oxidized in the citric acid cycle to yield the following: 15 × 3 NADH; 15 × 1 FADH₂, and 15 ATP molecules from the substrate level phosphorylation occuring at the succinylCoA synthetase catalyzed-reaction.

Total FADH₂ produced = 15 + 14 = 29 molecules of FADH₂

Total NADH produced = 45 + 14 = 59 molecules of NADH

The FADH₂ and NADH will each donate a pair of electrons to the electron transfer flavoprotein and mitochondrial NADH dehydrogenase respectively of the electron transport chain, and about 1.5 and 2.5 molecules of ATP are generated respectively when these electrons are transfered to molecular oxygen.

Thus, number of molecules of ATP generated by 29 molecules of FADH₂ = 1.5 × 29 = 43.5 molecules of ATP.

Number of molecules of ATP generated by 59 molecules of NADH = 2.5 × 59 = 147.5

Sum of ATP generated from FADH₂ and NADH = 43.5 + 147.5 = 191 ATP molecules

Total number of ATP molecules generated = 191 + 15 = 206 ATP molecules

Total number of ATP molecules generated from a 32-carbon fatty acid = 206 ATP molecules

Answer:

Using Newman projections, draw the most stable conformation for each of the following compounds.

(a) 3-methyl pentane, viewed along with the C2-C3 bond.

(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.

Explanation:

(a) The structure of 3-methyl pentane is shown below:

In Newman projection, the most stable conformation is staggard conformation.

In staggard conformation, the torsional strain is very less compared to eclipsed conformation.

(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.

Answer:

A wave character exhibited by all particles

Explanation:

The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.

The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.

These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.

Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.

Answer: The given electronic configuration is long hand notation.

Explanation:

Long-hand notation of representing electronic configuration is defined as the arrangement of total number of electrons that are present in an element.

Noble-gas notation of representing electronic configuration is defined as the arrangement of valence electrons in the element. The core electrons are represented as the previous noble gas of the element that is considered.

The given electronic configuration of potassium (K):  

The above configuration has all the electrons that are contained in the nucleus of an element. Thus, this configuration is a long-hand notation.

Answer:

Fission reaction occurs.

Explanation:

When a radioactive atom undergoes a nuclear decay event, spontaneous fission reaction occurs, the decaying nucleus undergoes a transformation in  the change in the number of protons in the nucleus. The fission process produces gamma photons, and releases a very large amount of energy. After the radiation stops, a stable element is obtained whereas the energy is released in the surrounding.

Answer:

the name for NO is nitrogen monoxide

Answer:

A

Explanation:

because CO2 is carbon dioxide and CO is carbon monoxide. mono meaning one which in this case is monoxide.

Answer:

See explanation

Explanation:

In writing the electron configuration of atoms, the core electrons are those electrons that occur in the inner shells. They do not participate in chemical reaction.

The valence electrons are those electrons that occur on the outermost shell of an atom and does participate in chemical reaction.

For Xe, the core electrons are; 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10 while the valence electrons are; 5s25p6

For Ca, the core electrons are; 1s2 2s2 2p6 3s2 3p6 while the valence electrons are 4s2.

Hence, there are 18 core electrons and 2 valence electrons for Ca and 46 core electrons for Xe and 8 valence electrons

Answer:

[tex]m_{H_2O}=73.0gH_2O[/tex]

Explanation:

Hello there!

In this case, since the formation of water from hydrogen and oxygen is:

[tex]2H_2+O_2\rightarrow 2H_2O[/tex]

Whereas we find a 2:2 mole ratio of hydrogen to water. In such a way, by using the Avogadro's number, the aforementioned mole ratio and the molar mass of water (18.02 g/mol), we obtain the following grams of water product:

[tex]m_{H_2O}=2.44x10^{24}molec*\frac{1molH_2}{6.022x10^{23}molec}*\frac{2molH_2O}{2molH_2}*\frac{18.02gH_2O}{1molH_2O}\\\\ m_{H_2O}=73.0gH_2O[/tex]

Regards!

Answer:

53.2 mL

Explanation:

As this problem deals with the neutralization of a strong monoprotic acid and a strong base, we can solve it by using the following formula:

Where in this case:

We input the data:

And solve for Vb:

Answer:

[tex]2.02gH_2[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to to calculate the mass of hydrogen gas by firstly setting up the undergoing chemical reaction:

[tex]2H_3PO_4+3Ca\rightarrow Ca_3(PO_4)_2+3H_2[/tex]

Thus, we apply the following stoichiometric setup, whereas the atomic mass of calcium is 40.08 g/mol, that of hydrogen is 2.02 g/mol and the mole ratio of these two substances is 3:3:

[tex]40.08gCa*\frac{1molCa}{40.08gCa}*\frac{3molH_2}{3molCa}*\frac{2.02gH_2}{1molH_2} \\\\=2.02gH_2[/tex]

Regards!

Answer:

none

Explanation:

the correct option would be Ar 3d3 4s2

Answer:

180 amu

C₆H₁₂O₆

Explanation:

Step 1: Determine the molecular mass of the compound

The sample has a mass (m) of 3.06 g and it contains (n) 0.0170 moles. The molar mass M is:

M = m/n = 3.06/0.0170 mol = 180 g/mol

Then, the molecular mass is 180 amu.

Step 2: Determine the molar mass of the empirical formula.

M(CH₂O) = 1 × M(C) + 2 × M(H) + 1 × M(O)

M(CH₂O) = 1 × 12 g/mol + 2 × 1 g/mol + 1 × 16 g/mol = 30 g/mol

Step 3: Determine the molecular formula

First, we will determine "n" according to the following expression.

n = molar mass molecular formula / molar mass empirical formula

n = 180 g/mol / 30 g/mol = 6

The molecular formula is:

n × CH₂O = 6 × CH₂O = C₆H₁₂O₆