Answer:
82.35%.
Explanation:
Mass of 1 molecule of ammonia
NH₃ = 14+3(1)
= 17
Calculating percentage by mass of N.
[tex]\%=\dfrac{\text{Mass of Nitrogen atom}}{\text{Mass of ammonia molecule}}\times 100[/tex]
[tex]\%=\dfrac{14}{17}\times 100\\\\=82.35\%[/tex]
So, the required percentage is 82.35%.
What is the empirical formula for propane?
Answer:
The empirical formula for propane is C3H8.
Answer:
Because propane is made up of only hydrogen and carbon _ the chemical formula is C3H8..
Can someone plz help me with this science
Answer:
The answer is A.
Explanation:
The answer is A because it is talking about a living organism.
Hope this helps! :)
How many moles are there in 2.3 x 10^23 formula units of NaCl?
Answer:
0.38 mol
Explanation:
Given data:
Number of formula units = 2.3×10²³
Number of moles = ?
Solution:
According to Avogadro number ,
1 mole contain 6.022×10²³ formula units.
2.3×10²³ formula units × 1 mol / 6.022×10²³ formula units
0.38 mol
Thus, 2.3×10²³ formula units of NaCl contain 0.38 moles of NaCl.
5.0g of copper is heated from 20 Celsius to 80 Celsius. How much energy it was used to heat Cu? (Specific heat capacity of Cu is 0.092 cal/g)
Answer:
the energy used to heat Cu is 27.6 Cal
Explanation:
given data
mass m = 5 g
Specific heat capacity of Cu = 0.092 cal/g
temperature T2 = 80 Celsius
temperature T1 = 20 Celsius
solution
we get here energy used to heat Cu that is express as
Q = m × c × ΔT ....................1
so here m = mass and c = specific heat capacity
and ΔT = T2 - T1
so put value in eq 1
Q = 5 × 0.092 × (80 - 20)
Q = 27.6 Cal
so that the energy used to heat Cu is 27.6 Cal
Please help and I will give brainliest!
I am going to put them in order
R r
R RR rR
r rR rr
the boiling point of isopropyl alcohol is 82.5°C. a student conducts an experiment and finds a boiling point of 83.1°C. what is the students percent error in this experiment?
A.0.6%
B. 0.7%
C. 1.0%
D. 99.3%
Answer:
B. 0.7%
Explanation:
Given data:
Actual boiling point = 82.5°C
Experimental boiling point = 83.1°C
Percent error = ?
Solution:
Formula:
Percent error = ( actual value - experimental value / actual value )×100
by putting values,
Percent error = (82.5°C - 83.1 °C /82.5°C) × 100
Percent error = 0.007 × 100
Percent error = 0.7 %
Negative sign shows that experimental value is greater than accepted value. It can not written in result.
If an 85.0 mL container of helium gas at standard pressure is heated from 20.oC to 91oC and the pressure is increased to 2.8 atm, then what would the new volume be for the He gas
Answer: V₂ = 37.71mL
Explanation: To determine the new volume of Helium gas, use the Combined Gas Law, which states the following relationship among pressure, volume and temperature:
[tex]\frac{P_{1}V_{1}}{T_{1}} =\frac{P_{2}V_{2}}{T_{2}}[/tex]
where index 1 relates to the initial state of the gas and index 2 to the final state of the gas.
Temperature is in Kelvin, so:
T = °C + 273
For this situation, standard pressure is 1 atm. Temperatures will be:
T₁ = 20 + 273 = 293 K
T₂ = 91 + 273 = 364 K
Solving:
[tex]V_{2}=\frac{T_{2}P_{1}V_{1}}{P_{2}T_{1}}[/tex]
[tex]V_{2}=\frac{364*1*85}{2.8*293}[/tex]
[tex]V_{2}=\frac{30940}{820.4}[/tex]
[tex]V_{2}=[/tex] 37.71
The new volume of He gas is 37.71 mL.
Question 10
1 pts
Which of the following statements is true about the mass of an atom?
The mass is equal to the neutrons plus the valance electrons
The mass of an atom is equal to the protons plus the neutrons
O The mass is equal to the protons plus the electrons
The mass is equal to the mass of the protons plus the valence electrons
+ Previous
Next >
Answer:
The mass of an atom is equal to the protons plus the neutrons
An element whose atoms have the electron configuration 2-8-18-1 is
А
a transition element
B
a noble gas
an alkali metal
D
an alkaline earth metal
Answer:
A transition element atomic number 29 copper Cu
Explanation:
A solution containing aluminium ions forms a white precipitate when a few drops of dilute sodium hydroxide solution are added to it. For example, sodium hydroxide solution reacts with aluminium sulfate solution. Sodium sulfate solution and solid aluminium hydroxide form. a Write a word equation for this reaction.
Answer:
See explanation
Explanation:
A word equation tries to depict a chemical reaction in words. Letters rather than only chemical formulas are used to show the reaction equation.
Now we want to write a word equation that shows the reaction of sodium hydroxide solution and aluminium sulphate solution:
Alumunium sulphate + sodium hydroxide ------>Aluminium hydroxide + sodium sulphate
What does x mean- like person x person?
Answer:
× = and
Explanation:
person and person
Specific gravity compares the density of a substance to the density of _____.
PLEASE HELP ILL GIVE YOU 15 POINTS !!!!!!
Answer:
Specific gravity compares the density of a substance to the density of air.
Specific gravity is compared the density of a substance to the density of water.
What is specific gravity?Specific Gravity is a dimensionless quantity that can be defined as the ratio of the density of a substance to the density of the water at a particular temperature.
The mathematical formula of the specific gravity can be written as:
Specific gravity = density of substance / density of water
The density of water at 4°C is used as a reference point as water has the highest density of 1000 kg/m³. Specific gravity or relative gravity does not have any dimension as it is a dimensionless quantity.
Specific gravity is the ratio of a substance’s density to that of water at a specific temperature. The temperature plays an important role in determining the specific gravity of a substance.
Therefore, specific gravity is a characteristic of the substance at a particular temperature and pressure that also affects the specific gravity.
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A 5.00 g sample of a pure substance powder is heated, and the powder leaves 4.63g of a shiny, metallic liquid. Is the powder an element or a compound? Explain
Answer:
compound
Explanation:
We already know that the original substance was pure. If this substance was pure and it was powdery in nature then we have a footing to start from.
Secondly, a 4.93 g of shinny metallic liquid was left behind. This shinny metallic liquid must be an element.
Since there was a loss in mass during heating, it follows that there were other components of the pure powder.
If the reasoning stated above is correct, then the substance is a compound.
If you knew the number of valence electrons in a nonmetal atom how would you determine the valence of the element. (Ignore hydrogen)
Answer:
The possible valances can be determined by electron configuration and electron negativity
Good Luck even though this was asked 2 weeks ago
Explanation:
All atoms strive for stability. The optima electron configuration is the electron configuration of the VIII A family or inert gases.
Look at the electron configuration of the nonmetal and how many more electrons the nonmetal needs to achieve the stable electron configuration of the inert gases. Non metals tend to be negative in nature and gain electrons. ( They are oxidizing agents)
For example Florine atomic number 9 needs one more electron to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Flowrine has a valance of -1
Oxygen atomic number 8 needs two more electrons to reach a valance number of 8 electrons to equal Neon atomic number 10. Hence Oxygen has a valance charge of -2.
Non metals with a low electron negativity will lose electrons when reacting with another non metal that has a higher electron negativity. When the non metal forms an ion it is necessary to look at the electron structure to determine how many electrons the element can lose to gain stability.
For example Chlorine which is normally -1 like Florine when it combines with oxygen can be +1, +3, + 5 or +7. It can lose its one unpaired electron, or combinations of the unpaired electron and sets of the three pairs of electrons.
Please help me, Thank you!
Answer:
B. Opposite
Explanation:
When one electron is transferred from sodium to chlorine, a pair of ions with oppositely charged ions is formed.
The electrostatic attraction between the ions forms a covalent bond between them.
When atoms lose or gain electrons, they become ions due to the charge imbalance within them. If sodium lose an electron, it becomes positively charged. when the electron is gained by chlorine, it becomes negatively charged These oppositely charged ions combined to form the ionic compound.Helga has a box. She wants to determine how much the box can hold. Which measurement should she calculate?
A) Length
B) Area
C) Volume
D) Perimeter
C) volume
Explanation:
hope it helps !
Answer:
Volume. "How much the box can hold" means how much matter can fit into the box
Which is not a property of an Acid?
A) low pH
B) Bitter
C) Burning Effects
D) Sour
Answer:
b bitter
Explanation: can i have brainlist please
Two important ways that energy is transported in the world around us is through
Explanation:
The two ways that energy can be transferred are by doing work and by heat transfer.
yrup, USP, is prepared by dissolving 850 g of sucrose in sufficient purified water to make 1000 mL of syrup. Syrup has a specific gravity of 1.31. How many milliliters of water are used to prepare two liters of syrup?
Answer:
920mL of water
Explanation:
To solve this question we need to find as first the mass that must be added of water to make 1000mL of syrup using specific gravity. Thus, we can know the volume of water that mus be added:
1.31 is 1.31g/mL. In 1000mL = 1310g/1000mL. As the mass added of sucrose is 850g, the mass of water = Volume of water is:
1310g - 850g = 460g of water = 460mL to make 1L, To make 2L the amount of water that must be added is:
460mL * 2 =
920mL of waterThe number of milliliters of water are used to prepare two liters of syrup is 920 mL of water.
Given that,
USP, is prepared by dissolving 850 g of sucrose in sufficient purified water to make 1000 mL of syrup. The Syrup has a specific gravity of 1.31.Based on the above information, the calculation is as follows:
1.31 is = 1.31g/mL.
Now
In 1000mL = [tex]1310g \div 1000mL[/tex].
Now if the mass is added so the mass of water should be equivalent to the volume of the water.
= 1310g - 850g
= 460g of water
Now
= 460mL for 1L,
To make 2L the water should be
= 460mL (2)
= 920mL of water
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18. How far does Larry move if traveling at 2m/s for 100s?
Answer:
200 m
Explanation:
Given data:
Speed of larry = 2 m/s
Time taken = 100 s
Distance travelled = ?
Solution:
Formula:
d = st
d = distance
s = speed
t = time
by putting values,
d = 2 m/s× 100 s
d = 200 m
I'd love some help please thank you
Answer:
the answer would be B
Explanation:
The move vigorously it is the higher the reactivity so if you put it in order the answer would be B
model and Schrodinger's atom model?
Explanation:
the model assumes that the electron is a wave and tries to describe the regions in space orb orbitals where most likely to be found
I JUST NEED HELP!!!! ASAP!!!!
Hydrogen cyanide has the chemical formula HCN. What's the formal charge on the N atom?
A)
+2
B)
0
C)
–2
D)
–1
Answer:
Formal charge = valance electron - nonbonding electron - (1/2)bonded electron
For nitrogen atom,
Formal charge = 5 - 2 - (1/2)×6
= 5-2-3
= 0
So, the formal charge on nitrogen atom in HCN is "0".
Explanation:
The formal charge on the N atom of hydrogen cyanide, HCN molecule is 0. Option B is correct.
Formal charge is defined as the individual charge of an atom. It is represented as:
Formal charge = valance electron - nonbonding electron - (1/2)bonded electron
The valence electrons in nitrogen atom is 5, there are 2 non bonding electrons and 6 bonded electrons on N atom in HCN,
Thus, For Hydrogen cyanide molecule, the formal charge on nitrogen atom is calculated as:
Formal charge
= 5 - 2 - (1/2)×6
= 5-2-3
= 0
So, the formal charge on nitrogen atom in HCN is "0".
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Which statement would be true if glucagon secretion were permanently inhibited, resulting in negative feedback?
Blood glucose levels would decrease.
Glycogen formation would be inhibited.
Insulin production would decrease.
The synthesis of fat would decrease.
Answer:
Insulin production would decrease.
Explanation:
Insulin and Glucagon work together to balance the sugar levels in the human blood stream. They work together in a negative feedback loop. Glucagon stimulates the liver to release glucose into the bloodstream in a process known as glycogenolysis. Insulin on the other hand is a sugar-lowering hormone.
Therefore, if glucagon secretion were permanently inhibited, insulin production would decrease as there would not be excess blood sugar to be reduced.
Answer:
Insulin production would decrease.
12. Draw the lewis structure for the element to help you answer the question *
Answer:hope it helps
Explanation:
Type the correct answer in the box.
Anna used 900 gallons of gasoline last year driving to and from work. This year, she changed jobs. She now uses only 600 gallons of gas annually.
If each gallon of gas releases 20 pounds of CO2 when burned, Anna reduced her CO2 emissions by ______%.
WILL MARK BRAINLIEST
Answer:The answer is 3.33%. Anna reduced her CO2 emissions by 3.33% from using 600 gallons of gas annually than from using 900 gallons of gasoline annually.
Explanation:
What does percent composition tell you about a substance?
O
A. It gives you the molecular formula of the substance,
B. It tells you what the substance is made of
O C. It gives you the total mass of the substance,
OD. It tells you how many moles are in the substance,
Answer:
Percent composition tells you which types of atoms (elements) are present in a molecule and their levels. Percent composition can also tell you about the different elements present in an ionic compound as well.ion:
Answer:
Explanation:hey
What is the oxidation state of the copper in the compund of CuCl²
Answer:
The oxidation number of metallic copper is zero. In its compounds, the most common oxidation number of Cu is +2. Less common is +1. Copper can also have oxidation numbers of +3 and +4
Explanation:
The air at the top of Mount Everest has pressures of 201.0 torr N2, 50.0 torr O2, 2.0 torr Ar, and 0.5 torr CO2. What is the total air pressure at the top of the highest peak in the world? Show all work to receive full credit.
Answer:
The total air pressure at the top of the highest peak in the world is 253.5 torr
Explanation:
The partial pressures of the gases present at the top of Mount Everest are;
Nitrogen, N₂ = 201.0 torr
Oxygen, O₂ = 50.0 torr
Argon, Ar = 2.0 torr
Carbon dioxide, CO₂ = 0.5 torr
By Dalton's law of partial pressure, the total pressure that a mixture of gases exerts is equal to the sum of the partial pressures of the individual gases
Mathematically, the law can be expressed as follows;
Total pressure, P = ∑P[tex]_i[/tex] = P₁ + P₂ + · · ·
From which we have;
The total air pressure at the top of the highest peak in the world, Mount Everest, [tex]P_{Total Mont Everest}[/tex] = The sum of the partial pressures of N₂, O₂, Ar, and CO₂
[tex]P_{Total Mont Everest}[/tex] = 201.0 torr + 50.0 torr + 2.0 torr + 0.5 torr = 253.5 torr
[tex]P_{Total Mont Everest}[/tex] = 253.5 torr = 0.33355263 atmosphere
Therefore, the total air pressure at the top of the highest peak in the world, [tex]P_{Total Mont Everest}[/tex] = 253.5 torr
The total air pressure at the top of the highest peak in the world is 253.5 torr.
What is Dalton's Law?Dalton's law of gases states that total pressure of any mixture of gases is equal to the sum of the partial pressures of individual gases.
Given that,
Partial pressure of Nitrogen gas = 201 torr
Partial pressure of Oxygen gas = 50 torr
Partial pressure of Argon gas = 2 torr
Partial pressure of Carbon dioxide gas = 0.5 torr
Total pressure at the top = 201 + 50 + 2 + 0.5 = 253.5 torr
Hence total pressure is 253.5 torr.
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What did most of the particles that Rutherford shot at the gold foil do? What was the surprising behavior of a few of the particles? What did he determine?
Answer:
Explanation:
Rutherford gold experiment gave the explanation to some observations made on atoms.
When he shot the gold foil, most of the [tex]\alpha[/tex]-particles passes through the foil undeflected nor absorbed. This faction of the particles propagated the foil as if there was nothing placed on their path.
The surprising behavior of a few of the [tex]\alpha[/tex]-particles was that they were deflected from their initial path on hitting the gold foil.
This implies that there is a part of the gold foil which has the same charge as the [tex]\alpha[/tex]-particles, and more massive than the particles. Thus, he was able to determine the nucleus of an atom.