Explanation:
The reason as to why the dark chocolate always melted the fastest was because of it's colour. It was a darker shade than the milk and white chocolate and the sun naturally absorbs dark colours therefore it melted faster.

https://prezi.com › science-project
What is the limiting reactant in the following equation? How much Fe2O3 will be produced if 2.1 g of Fe with 2.1 g of O2?
4 Fe + 3O2 —> 2Fe2O3
Answer:
Fe is limiting, and it will produce .0188 mols of Fe2O3
Explanation:
after you convert both Fe and O2 to mols by using their molar mass, you see there is less Fe than O2 so that is your limiting reactant. To find the amount of Fe2O3 you devide the limiting reactant by it's coefeciant (4) then multiply it by the products coefficant (2). Let me know if you have any questions
Study the reaction.
CH4 + 2O2 → CO2 + 2H2O
If 7.4 moles of carbon dioxide (CO2) form at the end of the reaction, how many moles of methane (CH4) and oxygen gas (O2) entered the reaction?
? moles of methane and
? moles of oxygen gas
7.4 moles of methane (CH₄)
14.8 moles of oxygen gas (O₂)
A compound is 70.0% iron and 30.0% oxygen. Its molecular mass is 479.1 g/mol. Determine the
molecular formula.
Answer:
[tex]Fe_6O_9[/tex]
Explanation:
Hello there!
In this case, since these problems about formulas, firstly require the determination of the empirical formula, assuming that the given percentages are masses, we can calculate the moles and mole ratio of oxygen to iron as shown below:
[tex]n_{Fe}=70/55.85=1.25\\\\n_O=30/16=1.875[/tex]
In such a way, by rounding to the first whole number we multiply by 8 and divide by 5 to obtain:
[tex]Fe_{2}O_{3}[/tex]
Whose molar mass is 159.69 g/mol and the mole ratio of the molecular to the empirical formula is:
479.1/159.69=3
Therefore, the molecular formulais:
[tex]Fe_6O_9[/tex]
Regards!
If an atom has more protons than an electron, its net charge will be
Answer: If an object has more protons than electrons, then the net charge on the object is positive. If there are more electrons than protons, then the net charge on the object is negative. If there are equal numbers of protons and electrons, then the object is electrically neutral.
Explanation:
Answer:
The net charge will be Positive
Explanation:
1. Calculation of equilibrium concentrations from Ka
Calculate the pH of a 1.0 M Acetic acid solution, using approximations. Ka = 1.8 x 10^-5
HC2H3O2+H2O⇆H3O(+)+C2H3O2(-)
Initial:
Change
at Equilibrium:
2. Calculation of species concentrations from Ka, using the quadratic formula
Calculate the pH of a 0.000010 M Acetic acid solution
HC2H3O2+H2O⇆H3O(+)+C2H3O2(-)
Initial:
Change:
at Equilibrium:
3. Calculation of Ka from the pH of a weak acid solution
Calculate the Ka of HNO2 if a 0.10 M HNO2 solution has a pH of 2.187
Initial:
Change:
at Equilibrium:
4. Calculation of Ka from the percent ionization
Calculate the Ka of Glycine if a 0.10 M Glycine solution is 4.1 x 10^-3 ionized
HGly+H2O⇆H3O(+)+Gly(-)
Initial:
Change:
at Equilibrium:
Determine the hydroxide ion concentration in
a solution that is 0.00034 M Ca(OH)2.
Answer in units of M.
Answer:
[tex]0.00068M[/tex]
Explanation:
Hello there!
In this case, according to the ionization of calcium hydroxide, a strong base:
[tex]Ca(OH)_2\rightarrow Ca^{2+}+2OH^-[/tex]
Thus, since there is a 1:2 mole ratio of calcium hydroxide to hydroxide ions, we apply the following proportional factor to obtain:
[tex]0.00034\frac{molCa(OH)_2}{L}*\frac{2molOH^-}{1molCa(OH)_2} \\\\=0.00068\frac{OH^-}{L}\\\\=0.00068M[/tex]
Regards!
Under the right conditions aluminum will react with chlorine to produce aluminum chloride.
2 Al + 3Cl2 -> 2 AlCl3
How many grams of aluminum chloride can be produced when 157.0g of aluminum react with excess chlorine?
Answer:775.9 g AlCl3
but what the steps pls help
Answer:
775.9 g
Explanation:
Step 1: Write the balanced equation
2 Al + 3 Cl₂ ⇒ 2 AlCl₃
Step 2: Calculate the mass corresponding to 157.0 g of Al
The molar mass of Al is 26.98 g/mol.
157.0 g × 1 mol/26.98 g = 5.819 mol
Step 3: Calculate the moles of AlCl₃ produced from 5.819 moles of Al
The molar ratio of Al to AlCl₃ is 2:2. The moles of AlCl₃ produced are 2/2 × 5.819 mol = 5.819 mol.
Step 4: Calculate the mass corresponding to 5.819 moles of AlCl₃
The molar mass of AlCl₃ is 133.34 g/mol.
5.819 mol × 133.34 g = 775.9 g
Consider the aldol-dehydration reaction. Draw the two possible products of the reaction between benzaldehyde and methylethylketone. (Do not draw the products of the double-condensation.)
Solution :
An [tex]$\text{aldol condensation}$[/tex] reaction is a type of [tex]\text{condensation reaction}[/tex] in organic chemistry where the enol or an enolate ion reacts with the carbonyl compound and forms a [tex]$\beta$[/tex]-hydroxyaldehyde or a [tex]$\beta$[/tex]-hydroxyketone, and then followed by a dehydration to give conjugated enone.
Benzaldehyde reacts with methylketone and forms two products:
Each of the given molecules contains a chirality center. Determine the relationship between the molecules. three images of 1-phenyl-1-propanol are given as compound A, B and C. Compound A has a dashed bond to the alcohol group, with the phenyl group on the left side and the remaining carbon chain on the right. Compound B has a dashed bond to the alcohol group, with the phenyl group on the right side and the remaining carbon chain on the left. Compound C has a wedge bond to the alcohol group, with the phenyl group on the right side and the remaining carbon chain on the left. Compound D is 1-phenyl-2-propanol with a dashed bond to the alcohol group and the phenyl on the left side and the remaining single carbon on the right side. What is the relationship between A and B
Answer:
They are enantiomers
Explanation:
So, according and based on the question, you want to know he relation only between A and B. I'll show you in the following drawing. If you want to know the relation with the others, post them on another question thread.
According to what you are stating here, we have a phenyl group on one side, then, the alcohol on one carbon, dashed (a side chain in the phenyl) and the rest of the chain on the same side. This will be compound A.
Compound B is the same as before, but the phenyl group on the other side. Like if you put Compound A in front of a mirror.
The key to know the relationship, is to see the chiral center. If the chiral center has the same configuration (R or S) as the other compound, then, both compounds could be the same molecule. If the configuration is different, then, we might facing enantiomers.
Let'´s see the original 1-phenyl-1-propanol, and formed compound A and B. (See picture below).
According to the picture, we can see that both compound has a different configuration in the chiral center (R and then S), and the only different between them is the fact that the phenyl group is on the other side. This is just like a mirror, so we can conclude that A and B are enantiomers.
Hope this helps
4. The device shown is a
that's used to measure the heat transferred by a reaction under constant volume.
A. bomb calorimeter
B. reaction vessel
C. thermometer
D. coffee-cup calorimeter
Answer:
The device shown is a calorimeter that used to measure the heat transfer by a reaction under constant volume.
Explanation:
Which equation represents the total ionic equation for the reaction of HNO3 and NaOH?
OH+ + OH -> H2O
O HNO3 + NaOH → NaNO3 + H20
OH + NO3 +Na+ + OH -> Na + NO3 + H20
OH + NO3 + OH →→ NO3 + H20
Answer:
H⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + OH⁻(aq) → Na⁺(aq) + NO₃⁻(aq) + H₂O(l)
Explanation:
First, we will write the molecular equation for the neutralization reaction between nitric acid and sodium hydroxide.
HNO₃(aq) + NaOH(aq) → NaNO₃(aq) + H₂O(l)
The total ionic equation includes all the ions and the molecular species.
H⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + OH⁻(aq) → Na⁺(aq) + NO₃⁻(aq) + H₂O(l)
Considering the temperature vs. time graph below, how does the temperature at the beginning of a change of state compare with the temperature at the end of the change?
- The temperature is always lower.
- The temperature is always the same.
- The temperature is usually lowest
- The temperature is usually higher.
The temperature at the beginning and the end of a change of state correct option is : The temperature is usually the same.
When looking at a temperature vs. time graph during a change of state, such as melting or boiling, the temperature remains constant throughout the duration of the change. This is because during a change of state, the heat energy is used to break the intermolecular bonds rather than increase the temperature. As a result, the temperature remains constant until the entire substance has completed the phase transition.At the beginning of the change of state, the substance is at its melting or boiling point, and the temperature remains constant as the substance absorbs heat energy to transition from a solid to a liquid (melting) or from a liquid to a gas (boiling). At the end of the change of state, the substance has fully transitioned, and the temperature remains constant until all the substance has completely melted or boiled.The correct option is: The temperature is usually the same.
For more such questions on temperature
https://brainly.com/question/4735135
#SPJ8
The temperature at the beginning of a change is always lower than the temperature at the end of the change option A
Does the temperature increase as the phase change progresses?The temperature doesn't vary during a phase transition, such as melting or boiling, until the phase change is finished. This is so that intermolecular forces can be broken rather than the average kinetic energy of the particles, which is related to temperature, being increased by the heat energy being applied to the substance.
But the temperature does increase from one point to the other on the heating curve.
Learn more about phase change:https://brainly.com/question/30368067
#SPJ1
If the pH of a solution is 6.96, then the solution is a
Answer:
acid
Explanation:
solution with pH less than 7 is acid
those with more that 7 is base
those equal to 7 is neutral
After extended stirring of a spatula sized portion of a solid drug in 100 mL of water, the drug appeared to be insoluble. Yet when the liquid was separated from the solid and heated, solid residue was observed forming as the liquid evaporated. This evidence suggests that the liquid portion of the mixture formed after stirring the drug with water was
Answer:
a saturated solution
Explanation:
A saturated solution is a solution that already contains just as much solute as it can normally hold at a given temperature.
When more solute is added to a saturated solution, the added solute does not dissolve.
The fact that when the liquid was separated and evaporated, some solid crystals were recovered means that the liquid has already dissolved the amount of solute that it can normally hold at that temperature. That is, the liquid is already a saturated solution hence more solute does not dissolve.
If 3.13 mol of an ideal gas has a pressure of 2.33 atm and a volume of 72.31 L, what is the temperature of the sample in degrees Celsius?
Answer:
382.49 C degree Celsius
Explanation:
Hello,
This problem deals with understanding the ideal gas law which hopes to predict how ideal gases might behave in any given condition. I listed the formula below and we are basically just going to solve for temperature by rearranging the equation as seen on the picture (there's also other rearranged ones in case you need to solve for those).
Universal gas constant R has a value of 0.0821 L * atm/(mole * K) when working with these given units so it will be part of this equation. R value changes based on what units you have.
T = PV/nR
= (2.33) (72.31) / (3.13)(0.0821)
= 655.64 K
Question is asking temperature in celsius so we employ the formula attached below:
C = K - 273.15
= 655.64-273.15
= 382.49 degree Celsius
382.49 degree Celsius is the answer!
What kind of substance is composed of two or more elements that are chemically combined?
Answer:
A molecule made of two or more elements chemically combined is a compound.
A molecule made of two atoms of the same element is just that an element.
A molecule made of two ( or more) elements is a compound.
Explanation:
How many particle in 3.5 of CO2
Answer:
Carbon dioxide (chemical formula CO
2) is an acidic colorless gas with a density about 53% higher than that of dry air. Carbon dioxide molecules consist of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace gas. The current concentration is about 0.04% (412 ppm) by volume, having risen from pre-industrial levels of 280 ppm.[8] Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, ice caps, glaciers and seawater. It is present in deposits of petroleum and natural gas. Carbon dioxide has a sharp and acidic odor and generates the taste of soda water in the mouth.[9] However, at normally encountered concentrations it is odorless.[1]
Carbon dioxide

Explanation:
As the source of available carbon in the carbon cycle, atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena. Plants, algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water, with oxygen produced as a waste product.[10]
CO2 is produced by all aerobic organisms when they metabolize organic compounds to produce energy by respiration.[11] It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals, including humans. Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread, beer and wine making. It is produced by combustion of wood, peat and other organic materials and fossil fuels such as coal, petroleum and natural gas. It is an unwanted byproduct in many large scale oxidation processes, for example, in the production of acrylic acid (over 5 million tons/year).[12][13][14]
It is a versatile industrial material, used, for example, as an inert gas in welding and fire extinguishers, as a pressurizing gas in air guns and oil recovery, as a chemical feedstock and as a supercritical fluid solvent in decaffeination of coffee and supercritical drying.[15] It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence. The frozen solid form of CO2, known as dry ice is used as a refrigerant and as an abrasive in dry-ice blasting. It is a feedstock for the synthesis of fuels and chemicals.[16][17][18][19]
Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming. Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid.[20]
When electrons move to a shell closer to the nucleus, energy is released as
Answer:
it is released as lower energy
lower energy will be the answer
hope it helps!!!!!
What type of molecule is acetylacetone?
Answer:
here is the answer
Explanation:
ketone is the answer
Help Me plz I'm so tired
Calculate the molarity of the two solutions.
The first solution contains 0.200 mol of NaOH in 2.00 L of solution.
The second is 15.5G of NaCl in 671mL of solution
Answer:
a) 0.100 M
b) 0.395 M
Explanation:
a) Calculate the molarity of a solution that contains 0.200 moles of NaOH (solute) in 2.00 L of solution
We will use the following expression for molarity.
[NaOH] = moles of solute / liters of solution
[NaOH] = 0.200 mol/2.00 L = 0.100 M
b) Calculate the molarity for a solution that contains 15.5 g of NaCl (solute, 58.44 g/mol) in 671 mL of solution
We will use the following expression for molarity.
[NaCl] = mass of solute / molar mass of solute × liters of solution
[NaCl] = 15.5 g / 58.44 g/mol × 0.671 L = 0.395 M
PLEASE HELP!! ORGANIC CHEMISTRY
A sample of a diatonic gas is loaded into an evacuated bottle at STP. The 0.25 L bottle contains 1.76 grams of the unidentified gas. Calculate the molar mass of the gas. What is the identity of the diatomic gas?
Answer:
(a) 157.7 g
(b) 7.04 g/dm³
Explanation:
(a) From the question,
According to Avogadro's Law,
1 mole of every gas at STP occupies a volume of 22.4 dm³
But mass of 1 mole of the diatomic gas = molar mass of the gas.
This Implies that,
The molar mass of the gas at STP occupies a volume of 22.4 dm³
From the question,
If,
0.25 L bottle contain 1.76 g of the gas,
Therefore,
Molar mass of the gas = (1.76×22.4)/0.25
Molar mass of the gas = 157.7 g.
(b) Density of the gas = mass/volume
D = m/v
Given: m = 1.76 g, v = 0.25 L = 0.25 dm³
Therefore,
D = 1.76/0,25
D = 7.04 g/dm³
_HCN+_CUSO4=_CUSO4+_CU(CN)2
What is the total number of moles of O2(g) that must react completely with 5.00 moles of C4H10(g)?
Answer:
32.5 moles of O2(g) are necessaries for a complete reaction
Explanation:
Based on the reaction of combustion of C4H10(g):
C4H10(g) + 13/2 O2(g) → 4CO2(g) + 5H2O(g)
1 mole of C4H10 needs 13/2 moles O2 for a complete reaction.
That means, the moles of O2 required for a reaction of 5.00 moles of C4H10 are:
5.00 moles C4H10 * (13/2mol O2 / 1mol C4H10) =
32.5 moles of O2(g) are necessaries for a complete reaction
8
What happens to solid waste in the circulatory system?
A it's expelled through the lungs
B
It pumps into the coronary circulation
C
It's dropped off in the kidneys
D
It's deposited in the aorta
Answer:c it’s dropped off in the kidneys
Explanation:
I took the quiz
The solid wastes are from the circulatory system is expelled to the kidney where, the nitrogenous wastes like urea and uric acid is excreted as urine from the body.
What is circulatory system ?A circulatory system is an organ system, where the blood is purified and oxygenation of blood takes place. Through circulatory system, the blood reaches throughout the body pumped from the heart through veins.
The organs included in circulatory system are lungs, heart, aorta, veins, blood vessels etc. There are various kinds of blood vessels each having specific functions.
There is a network of blood vessels including arteries and large veins, capillaries that join the venules and other veins. All the nutrients and ions are circulated throughout the body through blood and solid wastes are then expelled to kidney.
Kidney function as a sieve to clean the good fluid from waste products. Uric acid and urea along with water excreated as urine then. Thus, option C is correct.
To find more about circulatory system, refer the link below:
https://brainly.com/question/10103458
#SPJ6
A bottle labeled 0.01 M HCl is found in the laboratory. Assuming that the HCl is completely ionized calculate the [H+], [OH-] and the pH of the solution.
Answer:
[H⁺] = 0.01 M[OH⁻] = 1x10⁻¹² MpH = 2Explanation:
The assumption that the HCl is completely ionized means that the original concentration of the acid is equal to [H⁺].
[H⁺] = 0.01 MWith [H⁺], we can calculate [OH⁻], by using the following formula:
[H⁺] * [OH⁻] = 10⁻¹⁴0.01 M * [OH⁻] = 10⁻¹⁴[OH⁻] = 1x10⁻¹² MFinally we calculate the pH of the solution:
pH = -log[H⁺]pH = 217. Explain why chlorine gas can be prepared by electrolyzing an aqueous solution of NaCl
but fluorine gas cannot be prepared by electrolyzing an aqueous solution of NaF.
Answer:
Fluorine gas reacts with water.
What is the limiting reactant in the following equation? How much Fe2O3 will be produced if 2.1 g of Fe reacts with 2.1 g of O2?
4 Fe + 3O2 —> 2Fe2O3
Answer:
Fe is limiting reactant and 3.00g of Fe2O3 will be produced
Explanation:
To solve this question we must convert the mass of each reactant to moles and, using the reaction we can find limiting reactant. With moles of limiting reactant we can find moles of Fe2O3 and its mass as follows:
Moles Fe -Molar mass: 55.845g/mol-
2.1g * (1mol / 55.845g) = 0.0376 moles
Moles O2 -Molar mass: 32g/mol-
2.1g * (1mol / 32g) = 0.0656 moles
For a complete reaction of 0.0656 moles of O2 are needed:
0.0656moles O2 * (4mol Fe / 3 mol O2) = 0.0875 moles Fe
As there are just 0.0376 moles,
Fe is limiting reactant
The mass of Fe2O3 is:
Moles:
0.0376 moles Fe* (2mol Fe2O3 / 4mol Fe) = 0.0188 moles Fe2O3
Mass:
0.0188 moles Fe2O3 * (159.69g / mol) =
3.00g of Fe2O3 will be produced
[H+] [OH-] =
NEED HELP ASAP!!!
what is the partial pressure of each gas in a 26L container at 27°c that holds 5 moles of carbon dioxide,3.3 moles of nitrogen and 1.5 moles of hydrogen, and has a total pressure of 1.05
Answer:
pCO₂ = 0.54 atm
pN₂ = 0.35 atm
pH₂ = 0.16 atm
Explanation:
Step 1: Calculate the total number of gaseous moles
The total number of gaseous moles (n) is equal to the sum of the moles of the individual gases.
n = nCO₂ + nN₂ + nH₂ = 5 mol + 3.3 mol + 1.5 mol = 9.8 mol
Step 2: Calculate the partial pressure of each gas
We will use the following expression.
pi = P × χi
where,
pi: partial pressure of the gas i
P: total pressure (1.05 atm)
χi: mole fraction of the gas i
pCO₂ = 1.05 atm × (5 mol/9.8 mol) = 0.54 atm
pN₂ = 1.05 atm × (3.3 mol/9.8 mol) = 0.35 atm
pH₂ = 1.05 atm × (1.5 mol/9.8 mol) = 0.16 atm