How many moles of Au atoms are present in one ounce of pure gold? [1 oz = 28.4 g]
Answer:
3.36x10^27 atoms
Question 7 of 32
1 Point
What is the purpose of environmental regulations on chemicals?
A. To prevent all chemicals from entering the environment
B. To make the production of chemicals more costly
O C. To only allow the use of chemicals that help the environment
O D. To protect the environment from harmful chemicals
Answer:O D to protect the environment from harmful chemicals
Explanation:
Scientists disagree about the possible effects of global warming. Please select the best answer from the choices provided T F this would be appreciated
Scientific evidence for warming of the climate system is unequivocal.
The current warming trend is of particular significance because most of it is extremely likely (greater than 95 percent probability) to be the result of human activity since the mid-20th century and proceeding at a rate that is unprecedented over decades to millennia.
Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. This body of data, collected over many years, reveals the signals of a changing climate.
The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of many instruments flown by NASA. There is no question that increased levels of greenhouse gases must cause the Earth to warm in response.
Answer:
this is false
Explanation:
Which statement best describes an effect of tension acting on Earthis crudo
A. Layers of rock get pushed upward.
B. Layers of rock get folded.
c. One slab of rock gets pulled apart.
D. Two slabs of rock slide past one another.
Answer:
layers of rock get folded
Answer:
C.One slab of rock gets pulled apart
Explanation:
Which noble gases can form compounds and under what conditions? Give EXAMPLES
Answer:
Following
Explanation:
How are the water, carbon, and nitrogen cycles similar?
Answer:
There could be more than one answer. One answer is that water, carbon, and nitrogen all exist in different forms within one cycle. For example, water can exist in ice or liquid water and nitrogen can exist as NH4 or NO3. Another answer is that they both go through cycles that complete the process to produce the materials necessary for life on earth. Life is dependent on all three cycles.
Explanation:
Sorry if i'm late on answering this, i just got this right! Hope this helps more people.
The water, carbon, and nitrogen cycles are vital for life.
What is the significance of the water, nitrogen, carbon, and oxygen cycles in an ecosystem?Both plants and animals require water and the availability of water influences which species can be found in what amounts in a given location.Both plants and animals require oxygen to survive.Carbon is used in the construction of the great majority, if not all, organic molecules and compounds, as well as photosynthesis in plants.In the creation of organic compounds, nitrogen is also commonly used.Their cycles control the amount of water, nitrogen, carbon, and oxygen in a given environment, as well as how quickly those elements are restored over time. As a result, the cycles control both the species present in an ecosystem and their abundance, as well as how that ecosystem changes through time.Learn more about water, carbon, and nitrogen cycles here:-
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Plsss help if you know!!
The "calorie" used to measure the caloric content of foods is actually a kilocaloric (kcal) or 4184kJ. If the heat of cumbustion for sugar Is 5639kJ/Mol, why are people who are on limited calorie diets advised to limit thier fat intake?
Answer:
fat has twice the calories of carbohydrates per gram
Explanation:
The first point that we must make is that fat has twice the calories of carbohydrates per gram. This is why it is necessary for people who are dieting to limit their intake of fat. It is known that the calories contained in food are obtained from carbohydrates, proteins, and fats. Experts are of the opinion that one gram of carbohydrate contains 4 calories, one gram of protein contains 4 calories while one gram of fat contains about 9 calories. This is a little above two times the amount of calories in carbohydrates and proteins.
Since fat has twice as much calories as carbohydrates or sugar, taking them into the body will increase the 'calories' in the body thereby making the weight loss process difficult since the excess calories will now be stored in the body.
This is the reason why people who are on limited calorie diets are advised to limit their fat intake.
The reason why people who are on limited calorie diets are advised to limit their fat intake: because too much fat can raise the cholesterol level.
A calorie can be defined as a standard unit which is used for the measurement of the energy contained in a food.
Basically, the standard unit for the measurement of the caloric content in food is actually a kiloJoules (kJ) or kilocaloric (kcal).
A limited calorie diet is also referred to as a fat-restricted diet and it refers to an eating plan that completely limits the amount of fat that a person consumes on a daily basis.
Generally, people who are on limited calorie diets are advised to limit their fat intake because too much fat can raise the cholesterol level, which in turn increases their risk of having a heart disease.
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Which phrase describes an irregular galaxy?
O has a round shape
O contains many young stars
O has arms that extend from the center
O is larger than other types of galaxies
Answer: The answer would be B. contains many young stars.
Explanation:
There is very little new star formation in Irregular galaxies. Irregular galaxies have no particular shape and are smaller than other types of galaxies.
The irregular galaxy possess many young stars.
Irregular galaxyThey are the most unusual of galaxies.
They do not fit into either the elliptical or spiral galaxy categories.
They do not possess nice spiral arm, however, they do possess dark patches of dust and gas.
The irregular galaxies do not possess definite shape.
They comprise of several young stars as the extent of the formation of stars in irregular galaxies in brisk. They also do comprise old stars.
Thus, the correct statement is contains many young stars.
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Which element has a larger atomic radius than aluminum (AI)?
The Periodic Table
O A. Boron (B)
B. Silicon (Si)
O C. Nitrogen (N)
O D. Sodium (Na)
Answer:
The correct answer is D because i did this before and got it right.
Explanation:
Consider preparing ammonia gas by the following reaction:
N2(g) + 3H2(g) ===> 2NH3(g)
If you have 28.02 g of N2 and excess H2, how many grams of NH3(g) can be produced.
6.06g
14.01g
34.08 g
68.16 g
28.02g
Answer:
34.08g
Explanation:
(Take the atomic mass of N=14.0, H=1.0)
no. of moles = mass / molar mass
no. of moles of N2 used = 28.02 / (14x2)
= 1 mol
Since H2 is in excess and N2 is the limiting reagent, the no. of moles of NH3 produced depends on the no. of moles of N2 used.
From the equation, the mole ratio of N2:NH3 = 1: 2,
which means one mole of N2 produces 2 moles of NH3.
From the ratio, we can deduce the no. of moles of NH3 produced = 1 x 2 =2moles.
Mass = no. of moles x molar mass
Mass of NH3 produced = 2 x (14.0+1.0x3)
= 34g
≈34.08g (this happens because the atomic mass I took is only corrected to 1 decimal place, but in the end, this is only a very small error in the decimals. Make sure you take a look if the question provides the atomic mass:) )
The structural formula for 3-methyl-4-ethylbenzene-3-ene?
3-methyl-4-ethylhex-3-ene would be C9H18
Hope this helps!
3NO2(g) + H2O(l) — 2HNO3(aq) + NO(g)
a. How many grams of H2O are required to react with 28.0 g
of NO2?
b. How many grams of NO are produced from 15.8 g of H2O?
c. How many grams of HNO3 are produced from 8.25 g of NO2?
Answer:
A. 3.65 g of H2O.
B. 26.33 g of NO.
C. 7.53 g of HNO3.
Explanation:
The balanced equation for the reaction is given below:
3NO2(g) + H2O(l) —> 2HNO3(aq) + NO(g)
Next, we shall determine the masses of NO2 and H2O that reacted and the masses of HNO3 and NO produced from the balanced equation.
This is illustrated below:
Molar mass of NO2 = 14 + (16x2) = 46 g/mol
Mass of NO2 from the balanced equation = 3 x 46 = 138 g
Molar mass of H2O = (2x1) + 16 = 18 g/mol
Mass of H2O from the balanced equation = 1 x 18 = 18 g
Molar mass of HNO3 = 1 + 14 + (16x3) = 63 g/mol
Mass of HNO3 from the balanced equation = 2 x 63 = 126 g.
Molar mass of NO = 14 + 16 = 30 g/mol
Mass of NO from the balanced equation = 1 x 30 = 30 g.
Summary:
From the balanced equation above,
138g of NO2 reacted with 18 g of H2O to produce 126 g of HNO3 and 30 g of NO.
A. Determination of the mass of H2O required to react with 28.0 g
of NO2.
This is illustrated below:
From the balanced equation above,
138g of NO2 reacted with 18 g of H2O.
Therefore, 28 g if NO2 will react with = (28 x 18)/138 = 3.65 g of H2O.
Therefore, 3.65 g of H2O is needed for the reaction.
B. Determination of the mass of NO produced from 15.8 g of H2O.
This is illustrated below:
From the balanced equation above,
18 g of H2O reacted to produce 30 g of NO.
Therefore, 15.8 g of H2O will react to produce = (15.8 x 30)/18 = 26.33 g of NO.
Therefore, 26.33 g of NO were produced from the reaction.
C. Determination of the mass of HNO3 produced from 8.25 g of NO2.
This is illustrated below:
From the balanced equation above,
138g of NO2 reacted to produce 126 g of HNO3.
Therefore, 8.25 g of NO2 will react to produce = (8.25 x 126)/138 = 7.53 g of HNO3.
Therefore, 7.53 g of HNO3 were produced from the reaction.
Explain how a water strider can float on the surface of water without sinking.
Answer:
low weight and great area
Explanation:
Which of the following compounds would contain a total of three carbon atoms? A. 1-butene B. Propane C. 2-triene D. Heptane
Answer:
B- Proprane
Explanation:
The propane molecule has three carbon atoms
Calculate the molar mass for each of the following:
a. FeSO4, iron supplement
b. Al2O3, absorbent and abrasive
c. CH NOZS, saccharin, an artificial sweetener
Answer: a . 152g/mol b. 102g/mol c. 183g/mol
Explanation:
By stating the atomic masses of each element in the questions, we have;
Fe= 56, S= 32, O= 16, Al = 27, C = 12, H =1 , N = 14, therefore
(a). FeSO4 = 56 + 32 + (16 x 4) = 152g/mol
(b). Al2O3 = (27 x 2) + (16 x 3) = 102g/mol
(c). C7H5NO3S ( Saccharin, an artificial Sweetner) =
(12 x 7) + (1 x 5) + 14 + (16 x 3) + 32 = 183g/mol
Ammonia and oxygen react to produce nitric oxide and water. Which of the following chemical equations describes this reaction and is balanced?
A. 2NH3 (g) + 3O2 (g) —> 2NO (g) 4H20 (g)
B. 4NH3 (g) +5O (g) —> 4NO (g) + 6H2O (g)
C. 4NO (g) + 6H2O (g) —> 4NH3 (g) +52O (g)
D. 2NO(g) + 4H2O (g) —> 2NH3 +3O2 (g)
Answer:
Option B. 4NH3(g) + 5O2(g) —> 4NO(g) + 6H2O(g)
Explanation:
The reaction between ammonia, NH3 and oxygen, O2, will produce nitric oxide and water as shown below:
NH3(g) + O2(g) —> NO(g) + H2O(g)
Now, let us balance the equation.
This is illustrated below:
NH3(g) + O2(g) —> NO(g) + H2O(g)
There are 3 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 4 in front of NH3 and 6 in front of H2O as shown below:
4NH3(g) + O2(g) —> NO(g) + 6H2O(g)
There are 4 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 4 in front of NO as shown below:
4NH3(g) + O2(g) —> 4NO(g) + 6H2O(g)
Now, the are 2 atoms of O on the left side and a total of 10 atoms on the right side. It can be balance by putting 5 in front of O2 as shown below:
4NH3(g) + 5O2(g) —> 4NO(g) + 6H2O(g)
Now, we can see that the equation is balanced.
Therefore, option B gives the balanced chemical equation for the reaction.
Answer:
Answer: 4NH3(g) + 5O2(g) —> 4NO(g) + 6H2O(g)
Explanation: The reaction between ammonia, NH3 and oxygen, O2, will produce nitric oxide and water as shown below: NH3(g) + O2(g) —> NO(g) + H2O(g) Now, let us balance the equation. This is illustrated below: NH3(g) + O2(g) —> NO(g) + H2O(g) There are 3 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 4 in front of NH3 and 6 in front of H2O as shown below: 4NH3(g) + O2(g) —> NO(g) + 6H2O(g) There are 4 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 4 in front of NO as shown below: 4NH3(g) + O2(g) —> 4NO(g) + 6H2O(g) Now, the are 2 atoms of O on the left side and a total of 10 atoms on the right side. It can be balance by putting 5 in front of O2 as shown below: 4NH3(g) + 5O2(g) —> 4NO(g) + 6H2O(g) Now, we can see that the equation is balanced. Therefore, option B gives the balanced chemical equation for the reaction.
what’s the mass of 2.80 mol of ca
Answer:
112.22 g
Explanation:
mass = no. of moles x atomic mass
From the periodic table, we can see the atomic mass of Ca is 40.078.
Therefore,
mass = 2.80 x 40.078
= 112.22g (corrected to 2 decimal places.)
How many grams of lactic acid (C,H,O) are in 1 liter of a 0.5M solution of lactic acid?
And how many grams of lactic acid are in the above solution?
Answer:
a mole of lactic acid = 90 g
a 0.5 M solution would require 1/2 mol or 45 g
Explanation:
The molecular mass is 90 d, the combined atomic masses of its atoms.
There are 45 grams of lactic acid in 1 liter of a 0.5M solution of lactic acid
CALCULATE THE NUMBER OF MOLES IN THE SOLUTION:
The number of moles of lactic acid (C3H6O3) in the solution can be calculated by multiplying the molarity (M) of the solution by its volume (L). That is;no. of moles = molarity × volume
According to this question, the 1L lactic acid solution has a molarity of 0.5M, hence, the number of moles is calculated as follows:no. of moles = 1 × 0.5
no. of moles = 0.5moles of lactic acid
CALCULATE THE MASS OF LACTIC ACID:
The mass in grams of lactic acid can be calculated by multiplying the molecular mass of lactic acid (C3H6O3) by its number of moles i.e.Mass = no. of moles × molar mass
Molar mass of (C3H6O3) = 12(3) + 1(6) + 16(3)
= 36 + 6 + 48
= 90g/mol
Mass of lactic acid = 0.5 mol × 90 g/mol
Mass of lactic acid = 45grams.
Hence, there are 45 grams of lactic acid in 1 liter of a 0.5M solution of lactic acid.
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How many moles of 0.225 M CaOH2 are present in 0.350 L of solution?
Calculate the number of moles of solute (CaOH2)
( M CaOH2)
(0.350 L
) = mol CaOH2
Answer : The number of moles of solute [tex]Ca(OH)_2[/tex] is, 0.0788 moles.
Explanation : Given,
Molarity = 0.225 M
Volume of solution = 0.350 L
Formula used:
[tex]\text{Molarity}=\frac{\text{Moles of }Ca(OH)_2}{\text{Volume of solution (in L)}}[/tex]
Now put all the given values in this formula, we get:
[tex]0.225M=\frac{\text{Moles of }Ca(OH)_2}{0.350L}[/tex]
[tex]\text{Moles of }Ca(OH)_2=0.0788mol[/tex]
Therefore, the number of moles of solute [tex]Ca(OH)_2[/tex] is, 0.0788 moles.
Answer:
(0.225 M CaOH2) x (0.350 L) = 0.0788 mol CaOH2
Explanation:
edge 2021
For the second question: How many grams of CaOH2 are in this solution?
The molar mass of CaOH2 is 58.093 g/mol.
Answer:
(0.0787 mol CaOH2) x (58.093 g/mol) = 4.57g CaOH2
Explanation:
edge 2021
The table shows the electronegativity values of four unknown elements on the Pauling scale.
Electronegativity Values
Unknown Element Electronegativity
W
1.5
x
0.93
Y
2.0
Z
3.2
Which two elements are most likely to form an ionic bond together?
Answer:
X and Z
Explanation:
If the difference in electronegativity between two atoms is greater than 1.7, they will form an ionic bond.
W and Z: 3.2 - 1.5 = 1.7 no
X and Z: 3.2 - 0.93 = 2.27 yes
Y and Z: 3.2 - 2.0 = 1.2 no
W and Y: 2.0 - 1.5 = 0.5 no
X and Y: 2.0 - 0.93 = 1.07 no
W and X: 1.5 - 0.93 = 0.57 no
X and Z are most likely to form an ionic bond together.
Hope this helps.
Answer:
X and Z
Explanation:
ionic bonds form between elements with great differences between their respective electronegativity. X and Z have the greatest difference out of any other pair option given, thus they are most likely to bond ionically!
:) hope i help anyone
Please help me with question 7! A 140mL B 165mL C 140 L D 165L
Answer:
answer is c 140L
Explanation:
n=v/22.4L
Given the equation: N2 +202 --> 2NO2, what mass of oxygen is required to react completely with 59.443 g of
nitrogen?
Select one:
O a. 135.8
b. 93.3
O c. 118.8
O d. 263
PLEASE HELP
Answer:
A 135.8
Explanation:
Which statement correctly describes Earth’s magnetic field?
A) A compass can lead a hiker to the geographic North Pole.
B) The magnetic pole near the South Pole is a north pole.
C) Compasses point toward a magnetic pole that is a north pole.
D) Field lines circle Earth from east to west.
Answer:
B) The magnetic pole near the South Pole is a north pole.
Explanation:
The north pole on the compass is the geographical South Pole.
Hope it helps.
Answer:
The answer is B.
Explanation:
molar mass of c16h19n305s
Answer:
365.212
Explanation:
According to the given situation, the calculation of molar mass is shown below:-
Data provided
[tex]c_{16}\ h_{19}\ n_3\ o_5\ S[/tex]
Molar mass = 16 × 12 + 19 × 1.008 + 3 × 14 + 5 × 16 + 32.06
= 192 + 19.152 + 42 + 80 + 32.06
Molar mass = 365.212
Therefore for determining the molar mass we simply solve the above equation.
So, the correct answer is 365.212
Which of the following is a polar molecule?
O A. A carbon monoxide molecule (CO)
OB. A linear carbon dioxide molecule (CO2)
OC. A calcium oxide molecule (Cao)
O D. An oxygen molecule (0)
Answer:
D. An oxygen molecule (0)
Explanation:
Hope it helps.
How many moles of HCl are needed to completely react with 50.0 mL of 0.250 M NaOH solution? Group of answer choices 1.25 × 10-2 moles 1.25 × 101 moles 2.50 × 10-1 moles
Answer:
[tex]n_{HCl|=1.25\times 10^{-2}\ moles[/tex]
Explanation:
We know that , the reaction between NaOH and HCl is given as
[tex]HCL+NaOH\rightarrow NaCl+H_2O[/tex]
Form the above reaction we can say that
Number of moles of HCl =Number of moles of NaOH
[tex]n_{HCl} =n_{NaOH}[/tex]
Therefore
[tex]n_{HCl}=\frac{0.25\times 50}{1000}\ moles[/tex]
[tex]n_{HCl|=12.5\times 10^{-3}\ moles[/tex]
[tex]n_{HCl|=1.25\times 10^{-2}\ moles[/tex]
Therefore the numbers of moles needed of HCl wil be [tex]1.25\times 10^{-2}\ moles[/tex]
The number of mole of HCl needed to completely react with 50.0 mL of 0.250 M NaOH solution is 1.25×10¯² mole
We'll begin by calculating the number of mole of NaOH in the solution.
Volume = 50 mL = 50 / 1000 = 0.05 L
Molarity of NaOH = 0.250 M
Mole of NaOH =?Mole = Molarity x Volume
Mole of NaOH = 0.250 × 0.05
Mole of NaOH = 1.25×10¯² moleFinally, we shall determine the number of mole of HCl required to react with 1.25×10¯² mole of NaOH. This can be obtained as follow:
HCl + NaOH —> NaCl + H₂O
From the balanced equation above,
1 mole of NaOH reacted with 1 mole of HCl.
Therefore,
1.25×10¯² mole of NaOH will also react with 1.25×10¯² mole of HCl
Thus, the number of mole of HCl needed for the reaction is 1.25×10¯² mole
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Bee stings release methanoic acid which attacks the nerves in the skin. They can be
neutralized by applying a cream that contains
a) ammonia
b) vitamin C
c) sulphur dioxide
d) acetic acid (vinegar)
Answer:and so an acid should be applied to neutralize them and remove the pain.
Explanation:Bee and Wasp stings can be both painful and itchy, and are very common ... Many common household substances can be used for this, and vinegar and ... If you are near other Bees and Wasps,
Ammonia can be used to neutralise. Hence, option A is correct.
What is methanoic acid?It is the simplest carboxylic acid which consists of a single carboxylic acid group (COOH) which is attached to a hydrogen atom.
Ammonia is a great way to help neutralise the venom of a bee sting. All you need to do is create a thick paste out of baking soda and water and apply it to the sting.
Hence, option A is correct.
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What would form a solution
Two atoms have the same relative atomic mass but different chemical properties.
Which row about the proton and neutron numbers of these atoms is correct?
Answer:
A
Explanation:
Protons are the ones which give rise to different elements, hence different elements have different chemical properties. Therefore, the two atoms must have different proton numbers.
The relative atomic mass of an atom is determined by the mass of the neutrons and the protons. The mass of the electrons are not included due to their negligible mass (1/1840).
Hence, due to the different proton masses, the masses of the neutrons will also differ to ensure that both atoms have the same relative atomic mass.
The common isotopes of carbon are 12C and 13C. The average mass of carbon is 12.01115 amu. What is the abundance of the 13C isotope? A. 1.115% B. 98.885% C. 0.480% D. 99.52% Provide an explanation if possible. Thanks so much!
Answer:
The abundance of the 13C isotope is 1.115%
Explanation:
The given information are;
Common isotope of carbon are 12C and 13C
The formula for calculating the relative atomic mass is the observed mass multiplied by the percentage abundance at that mass given as follows;
M₁ X₁ + M₂X₂ = Relative atomic mass
Where:
X₁ + X₂ = 1 as these are percentage represented as fractions
Let M₁ = 12 for 12C and M₂ = 13 for 13C
X₁ = Relative abundance fraction of 12C
X₂ = Relative abundance fraction of 13C
We have;
12X₁ + 13X₂ = 12.01115.......................(1)
X₁ + X₂ = 1............................................(2)
Which gives;
X₁ = 1 - X₂
Substituting the value for X₁ in equation (1) gives;
12(1 - X₂) + 13X₂ = 12.01115
13X₂ - 12X₂ + 12 = 12.01115
X₂ = 12.01115 - 12 = 0.01115
Therefore, the relative abundance fraction of 13C 0.01115 which in percentage is 100 × 0.01115 = 1.115%.