Mrs. Kowolski surveyed all the students in her five classes, asking about their favorite desserts. She recorded the data in the pie graph below.
If a random student from any of the classes was asked "What is your favorite dessert?” what would most likely be the answer?
cake
berries
ice cream
brownies
Answer:
its ice cream
Explanation
im taking the exam <3 and there is more blue on the the graph then any other color so its queit obv.
Which of the following would result if the gases that are responsible for the greenhouse effect were removed from our atmosphere?
Answer:
Nighttime temperatures would be greatly reduced.
Explanation:
When methane is combusted in the presence of oxygen, water and
carbon dioxide are produced. State a practical use foe this reaction.
5.5x10² – 6.50x10'
Express the calculation in correct significant digits
Answer:
[tex]6.15x10^2[/tex]
Explanation:
Hello!
In this case, when performing mathematical operations with numbers in scientific notation, the first step is to write them in standard notation:
550 - 65.0
Thus, the result without any significant figures-based analysis is:
615.0
However, since 550 is significant to the ones and 65.0 to the tenths, we need to round the result to the bigger significance, in this case to the ones; therefore the appropriate result would be:
615
That in scientific notation would be:
[tex]6.15x10^2[/tex]
Best regards!
A chart with the densities of several substances is provided. A sample substance has a volume of 26cm3 and a mass of 205.4g. Which metal is it? D=M/V
Group of answer choices
Tin
Lead
Aluminum
Iron
Answer:
I think that it might be C. I'm not an expert so please don't blame me, I'm sorry if i'm wrong!
Explanation:
A chemist measures the amount of fluorine gas produced during an experiment. He finds that of fluorine gas is produced. Calculate the number of moles of fluorine gas produced.
Answer:
12.7 mol
Explanation:
A chemist measures the amount of fluorine gas produced during an experiment. He finds that 482. g of fluorine gas is produced. Calculate the number of moles of fluorine gas produced.
Step 1: Given data
Mass of fluorine (m): 482. g
Step 2: Determine the molar mass (M) of fluorine
Fluorine is a diatomic molecule of chemical formula F₂. Its molar mass is:
mF₂ = 2 × mF = 2 × 19.00 g/mol = 38.00 g/mol
Step 3: Determine the number of moles (n) corresponding to 482. g of fluorine
We will use the following expression,.
n = m/M
n = 482. g/(38.00 g/mol)
n = 12.7 mol
Which number should go in the blank?
- H₂ + O2 -> 2H₂O
O
2
3
1
Calculate the mole fraction of Ba Cl 2 in an aqueous solution prepared by dissolving 0.400 moles of Ba Cl 2 in 850.0 g of water.
Answer:
0.0084
Explanation:
The mole fraction of BaCl₂ (X) is calculated as follows:
X = moles BaCl₂/total moles of solution
Given:
moles of BaCl₂ = 0.400 moles
mass of water = 850.0 g
We have to convert the mass of water to moles, by using the molecular weight of water (Mw):
Mw of water (H₂O) = (2 x 1 g/mol)+ 16 g/mol = 18 g/mol
moles of water = mass of water/Mw of water = 850.0 g/(18 g/mol) = 47.2 mol
The total moles of the solution is given by the addition of the moles of solute (BaCl₂) and the moles of solvent (water):
total moles of solution = moles of BaCl₂ + moles of water = 0.400 + 47.2 mol = 47.6 mol
Finally, we calculate the mole fraction:
X = 0.400 mol/47.6 mol = 0.0084
When a substance is heated, the molecules move faster.
True or false
I think this statement is True.
Since water can be made of two other substances, it is not an element. Water is a ____________.
Answer:
water is a liquid
Explanation:
WATERRRDR ISSS A LIQUIIIDD
Water is a compound. A compound is made of two or more different elements chemically bonded together. Water is made up of two hydrogen molecules and one oxygen molecule.
Oxygen forms a number of compounds with nitrogen, many of which are quite reactive. One such compound is 36.86 % by mass N . Calculate the number of grams of oxygen present in a sample of this compound that contains 44.00 grams of N .
Answer:
75.37 g
Explanation:
From the question given above, the following data were obtained:
Percentage of nitrogen (N) in the compound = 36.86 %
Mass of nitrogen (N) in the compound = 44 g
Mass of oxygen (O) in the compound =?
Next, we shall determine the total mass of the compound. This can be obtained as follow:
Percentage of nitrogen (N) in the compound = 36.86 %
Mass of nitrogen (N) in the compound = 44 g
Total mass of compound (T) =?
Percentage of N = mass of N/ total mass × 100
36.86 % = 44 / T
36.86 / 100 = 44 / T
Cross multiply
36.86 × T = 100 × 44
36.86 × T = 4400
Divide both side by 36.86
T = 4400 / 36.86
Total mass = 119.37 g
Next, we shall determine the percentage of oxygen in the compound. This can be obtained as follow:
Percentage of N = 36.86 %
Percentage of O =?
Percentage of O = 100 – 36.86 %
Percentage of O = 63.14 %
Finally, we shall determine the mass of oxygen in the compound. This can be obtained as follow:
Percentage of O = 63.14 %
Total mass = 119.37 g
Mass of O =.?
Percentage of O = mass of O / total mass × 100
63.14 % = Mass of O / 119.37
Cross multiply
Mass of O = 63.14 % × 119.37
Mass of O = (63.14 / 100)× 119.37
Mass of O = 75.37 g
Thus, the mass of oxygen in the compound is 75.37 g
importance of solution in industry?
Answer:
Important industrial processes often utilize solution chemistry. The substance present in the major proportion is called the solvent, whereas the substance present in the minor proportion is called the solute.
Explanation:
What volume of nitrogen gas at STP would react with 37.2 g of magnesium to produce magnesium nitride
Answer:
11.58 L of N₂
Explanation:
We'll begin by calculating the number of mole in 37.2 g of magnesium. This can be obtained as follow:
Mass of Mg = 37.2 g
Molar mass of Mg = 24 g/mol
Mole of Mg =?
Mole = mass /Molar mass
Mole of Mg = 37.2 / 24
Mole of Mg = 1.55 moles
Next, we shall write the balanced equation for the reaction. This is illustrated below:
3Mg + N₂ —> Mg₃N₂
From the balanced equation above,
3 moles of Mg reacted with 1 mole of N₂.
Therefore, 1.55 moles of Mg will react with = (1.55 × 1)/3 = 0.517 mole of N₂
Thus, 0.517 mole of N₂ is need for the reaction.
Finally, we shall determine the volume of N₂ needed for the reaction as follow:
Recall:
1 mole of a gas occupies 22.4 L at STP.
1 mole of N₂ occupied 22.4 L at STP.
Therefore, 0.517 mole of N₂ will occupy = 0.517 × 22.4 = 11.58 L at STP
Thus, 11.58 L of N₂ is needed for the reaction.
The volume of nitrogen gas is 11.58 L of N₂
Calculation of volume:Mole = mass /Molar mass
= 37.2 / 24
= 1.55 moles
Now
1.55 moles of Mg will react with
= (1.55 × 1)/3
= 0.517 mole of N₂
Thus, 0.517 moles of N₂ is needed for the reaction.
Now
1 mole of a gas occupies 22.4 L at STP.
So,
Nitrogen gas is
= 0.517 × 22.4
= 11.58 L at STP
Learn more about the gas here: https://brainly.com/question/3134912
Select all the correct statements, there is more than one.
a. Experiments to determine mechanisms involve looking at indirect evidence to help support or disprove a proposed mechanism.
b. Most intermediates are not typically isolated to determine reaction mechanisms.
c. Transition states can be isolated and characterized to determine reaction mechanisms.
d. Carbocations are very reactive and are typically not isolated for analysis.
e. Carbocations can be routinely isolated (separated from a reaction mixture) and analyzed.
f. Scientists can prove that a specific mechanism exists.
g. Evidence of intermediates sometimes can be seen using techniques such as nuclear magnetic resonance spectroscopy.
Answer:
Experiments to determine mechanisms involve looking at indirect evidence to help support or disprove a proposed mechanism.
Most intermediates are not typically isolated to determine reaction mechanisms.
Carbocations are very reactive and are typically not isolated for analysis.
Scientists can prove that a specific mechanism exists.
Evidence of intermediates sometimes can be seen using techniques such as nuclear magnetic resonance spectroscopy
Explanation:
The study of reaction mechanism and chemical kinetics often form the main thrust of study in organic, inorganic and physical chemistry.
We often want to know the actual processes involved in the conversion of one specie to another. Unfortunately, this information may have to be obtained indirectly by certain chemical reactions or by the use of new instrumental methods such as nuclear magnetic resonance spectroscopy.
Many organic reactions have carbocation intermediates. These carbocations are relatively short-lived and are transient intermediates which are rarely isolated unless they are isolated in a molecular cage using a macromolecule or in superacids.
By intensive study, scientists can proof or disprove the authenticity of any proposed mechanism.
We must know that a transition state has partial bonds. It is often an extremely short-lived specie which cannot be isolated.
If 63.4 J of heat are added to a sample
of aluminum with a mass of 16.33 g, what is
its temperature change? The specific heat of
aluminum is 0.899 J/g °C
Answer:
dt = 4.32°C
Explanation:
Given the following data;
Mass = 16.33g
Quantity of heat, Q = 63.4J
Specific heat capacity = 0.899 J/g °C
To find the temperature change;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat. m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.Making dt the subject of formula;
[tex] dt = \frac {Q}{mc} [/tex]
Substituting into the equation, we have;
[tex] dt = \frac {63.4}{16.33*0.899} [/tex]
[tex] dt = \frac {63.4}{14.6807} [/tex]
dt = 4.32°C
Therefore, the change in temperature for this aluminum is equal to 4.32°C.
Which chemical equation represents a redox reaction
Answer:
The correct answer is option B, that is, CO + H2O → H2 + CO2
The redox reactions are regarded as the chemical reactions in which one reactant goes through the process of reduction and one reactant goes through the process of oxidation. The reduction reactions are the reactions in which gain of electrons occurs, while oxidation reactions are the reactions in which loss of electrons occurs.
From the mentioned options, only option B, that is, CO + H2O → H2 + CO2 is a kind of redox reaction. In this, the carbon is getting oxidized from +2 to +4 oxidation state, and hydrogen is getting reduced from +1 to 0 oxidation state. Hence, this reaction can be regarded as a redox reaction.
Explanation:
What are the products of the acid-base reaction of sodium carbonate with acetic acid?
Answer:
The mixture quickly foams up with carbon dioxide gas. If enough vinegar is used, all of the baking soda can be made to react and disappear into the vinegar solution. The reaction is: Sodium bicarbonate and acetic acid reacts to carbon dioxide, water and sodium acetate.
Explanation:
hope this helps
The products of photosynthesis are: Oxygen and carbon dioxide Carbon dioxide and glucose Оооо Carbon dioxide and water Oxygen and glucose
Answer:
oxygen and glucose
Explanation:
Photosynthesis produces oxygen and glucose. Glucose is a sugar which serves as "food" for the plant, and oxygen is just a by-product of the reaction.
How many grams of ^16N will be left from a 16.0 g sample after 21.6 s?
Answer:
2 g
Explanation:
From the question given above, the following data were obtained:
Original amount (N₀) = 16 g
Time (t) = 21.6 s
Amount remaining (N) =?
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Time (t) = 21.6 s
Half-life (t½) of ¹⁶N = 7.13 s
Number of half-lives (n) =?
n = t / t½
n = 21.6 / 7.13
n = 3
Finally, we shall determine the amount of ¹⁶N remaining. This can be obtained as follow:
Original amount (N₀) = 16 g
Number of half-lives (n) = 3
Amount remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2³ × 16
N = 1/8 × 16
N = 2 g
Thus, the amount of ¹⁶N remaining is 2 g
What are the names of the stable forms of oxygen?
Heres our final question.
1. Are all forms of conflict harmful to the organization? Why do you think so?
Answer:
Not all conflicts are harmful to an organization
Explanation:
Not all conflicts in an organization are harmful to that organization.
Conflicts can be good for an organization. Even though conflicts may always seem difficult, they could bring about growth and changes which are good for all organizations.
Conflict may have positive or negative results when they occur. How these conflicts are approached is what determines the result.
Positive conflict can be constructive, it births new ideas, gives opportunities for creativity and skills expansion and can solve continuous problems.
If you had a cup full of methanol and a pool full of methanol do you think they would have the same density or different density?
Answer:
same density
Explanation:
The amount of methanol is a quantitative characteristic, and by the other side the density of methanol is a qualitative characteristic. What I mean is that the amount of methanol is not related to the density; it would be the same density no matter how much methanol you have.
What volume of 0.450 M barium nitrate solution is needed to prepare 261.0 mL of a solution that is 0.272 M in nitrate
Answer:
78.8 mL .
Explanation:
Ba( NO₃ )₂ ⇄ Ba⁺² + 2 NO₃⁻
1 mole 2 mole
261 mL of .272 M in nitrate contains .261 x .272 gram -ions ( moles ) of NO₃⁻
= .071 gram-ions .
Let the volume of Ba(NO₃)₂ required be v litre .
moles of Ba( NO₃ )₂ in v volume = v x .45 moles
v x .45 moles of Ba( NO₃ )₂ will give 2 x v x .45 moles of NO₃⁻
According to question
2 x v x .45 = .071
v = .07888 litre
= 78.8 mL .
Harry vs Draco who has a better personality
Answer:
I-
Explanation:
Draco was better. Harry didn’t act too much like a main character and was kinda boring.. while Draco’s personality fit the role he played as the bully/mean kid and he still kept me interested.
At what temperature does iron turn into a gas? What does this tell you about the attraction between iron’s particles?
Answer: In gases the particles move rapidly in all directions, frequently colliding with each other and the side of the container. With an increase in temperature, the particles gain kinetic energy and move faster. The actual average speed of the particles depends on their mass as well as the temperature – heavier particles move more slowly than lighter ones at the same temperature. The oxygen and nitrogen molecules in air at normal room temperature are moving rapidly at between 300 to 400 metres per second. Unlike collisions between macroscopic objects, collisions between particles are perfectly elastic with no loss of kinetic energy.
Explanation: This is very different to most other collisions where some kinetic energy is transformed into other forms such as heat and sound. It is the perfectly elastic nature of the collisions that enables the gas particles to continue rebounding after each collision with no loss of speed. Particles are still subject to gravity and hit the bottom of a container with greater force than the top, and giving gases weight. Hope this helps with your problem! Byeeee :DDD
It's sad seeing people actually helping you lol.
and then you dont give brainliest. like ever.
Iron oxide is combined with carbon monoxide to produce pure iron and carbon dioxide gas. Physical or Chemical Change? Why?
Answer:
Chemical because it alters the identity of the substance
Calculate the numder of moles of 7.89X 10^11 atoms of Carbon.
Answer:
The numder of moles of 7.89*10¹¹ atoms of Carbon is 1.31*10⁻¹².
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number represents a quantity without an associated physical dimension, so it is considered a pure number that allows describing a physical characteristic without an explicit dimension or unit of expression. Avogadro's number applies to any substance.
Then you can apply the following rule of three, if by definition of Avogadro's number 6.023*10²³ atoms are present in 1 mole of Carbon, 7.89*10¹¹ atoms will be present in how many moles?
[tex]amount of moles=\frac{1 mole*7.89*10^{11} }{6.023*10^{23} }[/tex]
amount of moles=1.31*10⁻¹²
The numder of moles of 7.89*10¹¹ atoms of Carbon is 1.31*10⁻¹².
How many moles of hydrogen atoms are present in 2.41 x 10^24 molecules of CH3OH?
Answer:
16.0 mol H.
Explanation:
Hello!
In this case, since the Avogadro's number help us to compute the moles of methanol in the given molecules:
[tex]n_{CH_3OH}=2.41x10^{24}molecCH_3OH*\frac{1molCH_3OH}{6.022x10^{23}molecCH_3OH}=4.00molCH_3OH[/tex]
Thus, since 1 mole of methanol contains 4 moles of hydrogen atoms, we obtain:
[tex]n_H=4.00molCH_3OH*\frac{4molH}{1molCH_3OH}\\\\n_H=16.0molH[/tex]
Best regards!
How many oxygen molecules are produced when 3.2×1022 molecules of water decompose?
__H2O à __H2 + __O2
Answer: 1.6x10^22
Explanation: H2O —> H2 + 1/2O2 so half the number of water molecules
A 0.380 g sample of an unknown monoprotic acid is titrated with 0.300 M KOH to the equivalence point. It requires 20.1 mL of KOH to reach this point. Elemental analysis is also performed, showing that the acid contains 1.6% H, 22.2% N, and 76.2% O. Use this information to determine the molecular formula and the molar mass of the unknown acid.
Answer:
Explanation:
20.1 mL of .3 M KOH reacts with .38 g of sample monoprotic acid
20.1 mL of .3 M KOH = .021 x .3 mole of KOH
= .0063 mole of KOH
.0063 mole of KOH will react with .0063 mole of monoprotic acid
.0063 mole of monoprotic acid = .38 g
1 mole of monoprotic acid = 60.3 or 60 g
molecular weight of monoprotic acid = 60
Acid contains 1.6 % H , 22.2 % N , 76.2 % O
Ratio of weight of H , N , O in sample
= 1.6 : 22.2 : 76.2
Ratio of moles of H , N , O
1.6 / 1 : 22.2 / 14 : 76.2 / 16
1.6 : 1.585 : 4.76
= 1.6 / 1.585 : 1 : 4.76 / 1.585
= 1 : 1 : 3
Empirical formula
= HNO₃
Mol formula = [tex](HNO_3)_n[/tex] ( let )
Mol weight = n ( 1 + 14 + 3 x 16 )
= 63n .
Mol weight calculated above = 60
63n = 60
n = 1 ( approx )
Mol formula = HNO₃
Mol mass = 63 .
