Answer:
chắc là câu B í
Explanation:
3. A typical peanut butter and jelly sandwich contains 360 kcal, of which 160
kcal comes from fat. Given 1 kcal = 4.2 kJ, how many J of fat would there be
in one PB&J sandwich?
Explanation:
here's the answer to your question
A 45g Aluminum spoon (specific heat 0.88J/g degree Celcius) at 24 degrees Celcius placed in 180ml(180g) of coffee at 85 degrees Celcius and the temperature of the two become equal. What is the final temperature?
Answer:
82 °C
Explanation:
Let the specific heat capacity of the coffee be that of water which is 4.2 J/g °C.
Now, at the final temperature, heat gained by Aluminum spoon ,Q equals heat lost by coffee, Q'.
Q = -Q'
Q = m₁c₁(T₂ - T₁) where m₁ = mass of aluminum spoon = 45 g, c₁ = specific heat of aluminum = 0.88 J/g °C, T₁ = initial temperature of aluminum spoon = 24 °C and T₂ = final temperature of aluminum spoon.
Q' = m₂c₂(T₂ - T₃) where m₂ = mass of coffee = 180 g, c₂ = specific heat of coffee = 4.2 J/g °C, T₃ = initial temperature of coffee = 85 °C and T₂ = final temperature of coffee.
So, Q = -Q'
m₁c₁(T₂ - T₁) = -m₂c₂(T₂ - T₃)
Making T₂ subject of the formula, we have
m₁c₁T₂ - m₁c₁T₁ = -m₂c₂T₂ + m₂c₂T₃
m₁c₁T₂ + m₂c₂T₂ = m₂c₂T₃ + m₁c₁T₁
(m₁c₁ + m₂c₂)T₂ = m₂c₂T₃ + m₁c₁T₁
T₂ = (m₂c₂T₃ + m₁c₁T₁)/(m₁c₁ + m₂c₂)
substituting the values of the variables into the equation, we have
T₂ = (180 g × 4.2 J/g °C × 85 °C + 45 g × 0.88 J/g °C × 24 °C )/(45 g × 0.88 J/g °C + 180 g × 4.2 J/g °C)
T₂ = (64260 J + 950.4 J)/(39.6 J/°C + 756 J/°C)
T₂ = 65210.4 J/795.6 J/°C
T₂ = 81.96 °C
T₂ ≅ 82 °C
name some examples of chemical solutions and maybe give a clear explanation as to what chemical solutions are
Answer:
Some examples of solutions are salt water, rubbing alcohol, and sugar dissolved in water. ... In our example of salt water, the solute is the salt. Solvent: this is the substance that makes up the majority of the solution. This is the part where the solute is dissolved.
Explanation:
I hope they should be right answer
22.4l of ammonia is reaxts with 1.406 mole of oxygen to produce NO and h2o .1.what volume of no is produced at ntp
Answer:
The volume of NO is 22.4L at STP
Explanation:
Based on the reaction:
2NH3 + 5/2O2 → 2NO + 3H2O
2 moles of NH3 react with 5/2 moles of O2 to produce 2 moles of NO.
To solve this question, we need to find the moles of each reactant in order to find the limiting reactant as follows:
Moles NH3 -Molar mass: -17.01g/mol-
Using PV = nRT
PV/RT = n
Where P is pressure = 1atm at STP
V is volume = 22.4L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 273.15K
1atm*22.4L/0.082atmL/molK*273.15K = n
n = 1.00 moles of NH3
For a complete reaction of 1.00 moles of NH3 are needed:
1.00 moles NH3 * (5/2moles O2 / 2moles NH3) = 1.25 moles of O2
As there are 1.406 moles of O2, the limiting reactant is NH3
The moles of NO produced are the same than moles of NH3 because 2 moles of NH3 produce 2 moles of NO. The moles of NO are 1.00 moles
And as 1.00moles of gas are 22.4L at STP:
The volume of NO is 22.4L at STPIf 56 grams of carbon monoxide burns in oxygen to produce 88 grams of carbon dioxide, the mass of oxygen involved in the reaction is
grams.
The answer is 32 grams!
hope I helped
Potassium impart purple colour but beryllium do not impart any colour to the flame.Why?
Answer:
The electrons in beryllium and magnesium are too strongly bound to get excited by flame. Hence, these elements do not impart any color.hii pls help me to balance the equation thanksss
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[tex]\pmb{\red{\boxed{\sf{Na_{2}O(s)+H_{2}O(l)\dashrightarrow 2NaOH(aq) }}}}[/tex]
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What is the equivalent to √-80
Answer:
4i[tex]\sqrt{5}[/tex]
Explanation:
[tex]i^{2}[/tex]= -1
A molecular orbital is a region of space in a covalent species where electrons are likely to be found. The combination of two atomic orbitals always forms two molecular orbitals; the bonding molecular orbital, which is _____ in energy, and the antibonding molecular orbital, which is _____ in energy, than the original atomic orbitals.
Answer:
bonding molecular orbital is lower in energy
antibonding molecular orbital is higher in energy
Explanation:
Electrons in bonding molecular orbitals help to hold the positively charged nuclei together, and they are always lower in energy than the original atomic orbitals.
Electrons in antibonding molecular orbitals are primarily located outside the internuclear region, leading to increased repulsions between the positively charged nuclei. They are always higher in energy than the parent atomic orbitals.
Which of the following structures in the human eye most likely functions in a way to help humans see clearly in different levels of light? A. The iris, or the colored portion of the eye
B. The white area
C. The eyelid
D. The pupil, or the dark portion at the center of the eye
D. the pupil or the dark portion at the center of the eye
(Q014) Silicates a. are classified on the basis of what kind of metals they contain. b. form through the evaporation of water. c. are a large category of minerals that includes the common minerals calcite and dolomite. d. have the silicon-oxygen tetrahedron as their structural unit.
Answer: d. have the silicon-oxygen tetrahedron as their structural unit.
Explanation:
Silicates are anions that have both Oxygen and Silicon as the basis of their structure. These two form a tetrahedron type structure that enable them to be useful for a whole lot of things.
Silicates are very abundant on Earth as they comprise around 95% of the Earth's crust as well as the upper mantle which explains why they are mostly found in igneous rocks.
How does adding oxygen (O) to this reaction change the equilibrium?
2s02(g) + O2(g) = 2s03(8)
Answer:
The equilibrium shifts right to produce more SO3 molecules.
Explanation:
The equilibrium law states that when a system encounters a disturbance like a temperature, concentration, or pressure modifications, it will react to restore a new state of equilibrium.
Adding a reactant such as oxygen (O2) will shift the reaction in the direction of the product, on the basis of the equilibrium law. Therefore, the equilibrium will move toward the product side.
I forgot to add the answers i had to my question (While a balloon is being filled, if the temperature of the air in the balloon increases, what happens to it’s volume)
A) It stays the same
B) It deflates
C) It decreases
D) It increases
The correct answer is D ... and if the answer was added to the word "explode" .. it would have been more correct .
please answer this questions soon
i will mark him or her brillient
Answer:
1)Or
d.Sublimation
2)
b.iodine is the solute and alcohol is solvent
3)
a.compostion of solute
Answer:
1) a) centrifugation
OR
b) sublimation
2) a) iodine is the solute and alcohol is solvent
3) a) concentration of soLute
How many moles of Cd and of N are contained in 132.4 g of Cd(N03)2-4H20? (b) How many molecules of water of hydration are in this same amount?
Answer: The given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
Explanation:
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] ......(1)
Given mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 132.4 g
Molar mass of [tex]Cd(NO_3)_2.4H_2O[/tex] = 308.5 g/mol
Plugging values in equation 1:
[tex]\text{Moles of }Cd(NO_3)_2.4H_2O=\frac{132.4g}{308.5g/mol}=0.430 mol[/tex]
1 mole of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 1 mole of Cd, 2 moles of nitrogen atom (N), 10 moles of oxygen atom (O) and 8 moles of hydrogen atom (H).
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex](1\times 0.430) = 0.430mol[/tex] of Cd and [tex](2\times 0.430)=0.86mol[/tex] of N
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 0.430 moles of [tex]Cd(NO_3)_2.4H_2O[/tex] will contain = [tex]\frac{6.022\times 10^{23}}{1mol}\times 0.430mol=2.59\times 10^{23}[/tex] number of water molecules.
Hence, the given amount of [tex]Cd(NO_3)_2.4H_2O[/tex] contains 0.430 moles of Cd, 0.860 moles of N and [tex]2.59\times 10^{23}[/tex] molecules of water.
H3C6H507 + H2O + H3O+ + H2C6H507
acid
base
Explanation:
an acid will give away a proton and become a conjugate base.
A base will accept a proton and become a conjugate acid.
What are the differences between molecule of an elements and molecules of a compound?
a compound is a pure substance made up of two or more elements chemically combined a molecule is defined as the smallest particle of an element which can exist separately elements are pure substances which can not be split into simple substances by chemical means the atom is defined as the smallest particle of an element which can take part in a chemical change so I think the difference between the molecule of a compound is bigger than the molecule of a compound
Which fossil fuel is the remains of ancient plants?
A. Coal
B. Petroleum
C. Natural Gas
A. Coal
Others are animal remains
The fossil fuel which is the remains of ancient plants is: A. Coal.
Non-renewable energy can be defined as a type of energy that is mainly generated through artificial sources or from the remains of ancient plants.
Hence, a non-renewable energy cannot be replenished or renewed like the renewable energy sources.
Basically, some examples of a non-renewable energy include:
Natural gas.Petroleum.Coal.Other fossil fuels.Coal deposits are typically petrified peat swamps and peat is generated from decaying plants.
Also, coal has been discovered to be a fossil fuel that contain the remains of ancient plants, based on radioactive dating.
Read more: https://brainly.com/question/22527860
calculate the maximum mass of ethanol that could be obtained from 30.0g of glucose
Answer:
15.3g
Explanation:
C6H12O6 → 2C2H5OH + 2CO2
1 mol C6H12O6 = 180g
1 mol CH3-CH2-OH = 46g
From 180g glucose ethanol can get = 92g
30g glucose ethanol gives us = (92*30)/180 = 15.33g
PLZ HELP ME Which of the following accurately descnbes the function of the nervous system? O
A To help parts of the body communicate
B. To prevent and fight disease C:
To allow the body to move O
D. To provide support for the body SUNT
Answer:
A
Explanation:
the nervous system helps parts of the body communicate.through nerves.
I hope this helps
PLZ HELP Question 14 of 25 What is the name for a representation of the physical world?
A. Model
B. Compound
C. Atom
D. Alloy SUBMIN
Answer:
Model
Explanation:
A model of anything is something you make to represent it in it's physical world form
ASAP worth 15 points also
A newspaper story describing the local celebration of Mole Day on October 23 (selected for Avogadro's number, 6.02 X 10^ 23 ) attempting to give the reader a sense of the size of the number by stating that a mole of M&Ms would be equal to 18 tractor trailers full. Assuming that an M&M occupies the volume of about 0.5 cm ^ 3 calculate the dimensions of a cube required to hold one mole of M&Ms. Would 18 tractor trailers be sufficient?
Answer:
The answer is "670.176 km".
Explanation:
Volume of the occupies of one M & M= 0.5 \ cm^3\\\\
M&M 1 mole[tex]= 6.02 \times 10^{23}\\\\[/tex]
Calculating volume of M& M mole[tex]= 0.5 \ cm^3 \times 6.02 \times 10^{23}=3.01 \times 10^{23}\ cm^3\\\\[/tex]
Calculating the cube mole[tex]L^3= 3.01 \times 10^{23}\ cm^3\\\\[/tex]
[tex]L=6.70176 \times 10^{7}\ cm\\\\[/tex]
[tex]=6.70176 \times 10^{7}\ cm \times \frac{1\ m}{100\ cm}\\\\=670176\ m\\\\=670.176 \ km[/tex]
Therefore 18 tractor trailers wouldn't be sufficient.
calculate the mass of magnesium needed to make 25g of magnesium oxide
Explanation:
here's the answer to your question about
what are the defects of mendeleev's periodic table
Answer:
1 Anomalous Pairs. The rest of the pairs of elements don't follow the follow Mendeleev's Principles . they are :
2Grouping of chemically dissimilar elements.
3Position of Isotopes.
4Electronic arrangement.
5Separation of chemically similar elements.
6The position of hydrogen.
A gas occupies 210 mL at -73°C to have the same gas occupy 360 mL:
should the temperature be increased or decreased?
what is the new temperature? __ K
Answer:
a. The temperature should be increased.
b. 342.86K
Explanation:
Using Charles law equation as follows:
V1/T1 = V2/T2
Where;
V1 = initial volume (mL)
V2 = final volume (mL)
T1 = initial temperature (K)
T2 = final temperature (K)
According to this question, the following information were given:
V1 = 210mL
V2 = 360mL
T1 = -73°C (-73 + 273 = 200K)
T2 = ?
Using V1/T1 = V2/T2
210/200 = 360/T2
Cross multiply
200 × 360 = 210 × T2
72000 = 210T2
T2 = 72000/210
T2 (new temperature) = 342.86K
Sodium nitrate is used in fertilizers, explosives, and glass manufacturing. Give the formula for this compound
How many moles are in 1.7 g of sodium nitrate?
Explanation:
The molecular formula for Sodium Nitrate is NaNO3. The SI base unit for amount of substance is the mole. 1 grams Sodium Nitrate is equal to 0.011765443644878 mole.
What does it mean to view something from a frame reference
Answer:
In physics, a frame of reference, or reference frame, is a perspective that one uses to determine if an object is moving.
For example, when you see a ball roll down a street, you can tell the ball is moving because the frame of reference is the streets, whatever may be on the side of the roads, or the Earth
The seeds of a dandelion are wispy and very light. A single dandelion produces many seeds. How does the structure of the seeds relate to the dandelion's method of spreading seeds?
A Dandelion seeds are spread mainly by the wind. Because they are light, the wind can carry them. The dandelion produces many seeds because not all seeds will land in a good location to sprout.
B. Dandelion seeds are spread primarily by becoming attached to animals' fur. Because they are light, the animals can cany many without noticing. The dandelion produces many seeds because not all seeds will land in a good location to sprout
C. Dandelion seeds are spread mainly by animals that eat them Because they are light the animals will eat many seeds. The dandelion produces many seeds in order to outcompete other plants for resources
D. Dandelion seeds are spread primarily by moving water. Because they are light, they will float on the water. The dandelion produces many seeds in order to outcompete other plants for resources. SIMIT
Answer:
the answer will be number...D
Answer:
The answer is A
Explanation:
Because dandelions are wispy and very light, the slightest gasp of wind helps carry the dandelions to new locations and help reproduce the seed into a new dandelion.
What is a cold front? What kind of weather can you expect there?
