Answer:
The given sample is aluminum.
Explanation:
Given data:
Mass of unknown sample = 54 g
Volume of given sample = 20cm³
Is sample is Al = ?
Solution:
In order to solve this problem we must know the density of Al from literature.
density of Al = 2.7 g/cm³
Now we will calculate the density of given unknown sample.
d = m/v
d = 54 g/ 20cm³
d = 2.7 g/cm³
Thus given sample is aluminum.
Compound Lattice Energy (kJ/mol) Compound Lattice Energy (kJ/mol) LiF 1030 NaCl 788 LiCl 834 MgCl2 2326 LiI 730 AlCl3 5376 Lattice Energy 1 Lattice Energy 2 For the lattice energies given above … in Lattice Energy 1, explain why LiF has a greater lattice energy than LiI in Lattice Energy 2, explain why NaCl has a smaller lattice energy than AlCl3
Answer:
The lattice energy decreases down the group and increases across the period, therefore, the lattice energy of LiF > lattice energy of LiI, and the lattice energy of NaCl < the lattice energy of AlCl₃
Explanation:
The given parameters are;
Compound [tex]{}[/tex] Lattice Energy (kJ/mol)
LiF [tex]{}[/tex] 1030
NaCl [tex]{}[/tex] 788
MgCl₂ [tex]{}[/tex] 2326
LiI [tex]{}[/tex] 730
AlCl₃ [tex]{}[/tex] 5376
Lattice is the energy that must be added in order to split one mole of a ionic solid compound into gaseous ions
Given that the force of attraction between charges is inversely proportional to the square of the distance separating the charges, we have that as the atomic radius increases progressively down the group, the lattice energy decreases, therefore, LiF which has a shorter inter nuclear distance than LiI due to fluorine, F, being higher up on the periodic table than iodine, I, has a greater lattice energy than LiI
Similarly, given that the atomic radius decreases across the period, and that sodium, Na, comes before aluminum, Al, as we move across period 3, of the periodic table, the inter nuclear distance between atoms of in NaCl is larger than the internuclear distances between the atoms of AlCl₃, as well as the presence of more chlorine atoms in AlCl₃ than in NaCl, the lattice energy of NaCl is smaller than the lattice energy of AlCl₃.
Can regions that experience extreme low temperatures be located right
next to regions that experience very high temperatures?
Yes
No
Answer:No
Explanation:
Well yes but no, There cant be high tempreture that is 100 degrees and a low tempreture that is 20 degress, there has to be a mid inbetween both, they cant be next to eachother.
5
Calculate the mass of a liquid with a density of 2.5 g/mL and a volume of 15 mL.
7
Calcule la masa de un líquido con una densidad de 2.5 g/mL y un volumen de 15 mL.
A. 375 g
B. 3.75 g
C. 37.5 g
Answer:
The answer is option CExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume of liquid = 15 mL
density = 2.5 g/mL
We have
mass = 15 × 2.5
We have the final answer as
37.5 gHope this helps you
A sample of 4.0 mol of neon gas at a pressure of 2.5 atm is injected into a container at
25°C. What is the volume of the container?
Answer:
The volume of container is 39.14 L.
Explanation:
Given data:
Number of moles of neon = 4.0 mol
Pressure of gas = 2.5 atm
Temperature of gas = 25°C
Volume of container = ?
Solution:
we will use general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
25+273 = 298 K
Now we will put the values in formula.
2.5 atm × V = 4.0 mol × 0.0821 atm.L/ mol.K × 298 K
V = 97.86 atm.L /2.5 atm
V = 39.14 L
The volume of container is 39.14 L.
PLEASE HELP!!!!!
How much energy is needed to raise the temperature of 2.5 L of water from 20 C to 50 C? (anwer must be in Joules)
Answer:
8368 Joules
Explanation:
May I have some salt? (What is salt consisted of?)
Answer: Salt is primarily composed of sodium chloride.
Explanation:
Which of the following is a correctly written chemical equation that demonstrates the conservation of mass?
O A. H2 + O2 + H2O
B. Mg + HCl + H2 + MgCl2
C. KC 103 → KC1 + O2
OD. H2O + CO2 + H2CO3
Answer:
Option D is correct.
H₂O + CO₂ → H₂CO₃
Explanation:
First of all we will get to know what law of conservation of mass states.
According to this law, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
Example:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
Now we will apply this law to given chemical equations:
A) H₂ + O₂ → H₂O
There are two hydrogen and two oxygen atoms present on left side while on right side only one oxygen and two hydrogen atoms are present so mass in not conserved. This equation not follow the law of conservation of mass.
B) Mg + HCl → H₂ + MgCl₂
In this equation one Mg, one H and one Cl atoms are present on left side while on right side two hydrogen, one Mg and two chlorine atoms are present. This equation also not follow the law of conservation of mass.
C) KClO₃ → KCl + O₂
There are one K, one Cl and three O atoms are present on left side of chemical equation while on right side one K one Cl and two oxygen atoms are present. This equation also not following the law of conservation of mass.
D) H₂O + CO₂ → H₂CO₃
There are two hydrogen, one carbon and three oxygen atoms are present on both side of equation thus, mass remain conserved. Thus is correct option.
The chemical reaction that follows the conservation of mass has been the formation of hydrogen carbonate. Thus, option D is correct.
The conservation of mass states that the mass of the reactant and products has been equal. The mass can be calculated in terms of the number of atoms.
(A) [tex]\rm H_2\;+\;O_2\;\rightarrow\;H_2O[/tex]
The number of atoms of Hydrogen:
Reactant = 2
Product = 2
The number of atoms of Oxygen:
Reactant = 2
Product = 1
The number of atoms of products and reactant is not equal, Thus, the reaction did not follow the conservation of mass.
(B) [tex]\rm Mg\;+\;HCl\;\rightarrow\;H_2\;+\;MgCl_2[/tex]
The number of atoms of Mg:
Reactant = 1
Product = 1
The number of atoms of H:
Reactant = 1
Product = 2
The number of atoms of Cl:
Reactant = 1
Product = 2
The number of atoms of products and reactant is not equal, Thus, the reaction did not follow the conservation of mass.
(C) [tex]\rm KClO_3\;\rightarrow\;KCl\;+\;O_2[/tex]
The number of atoms of K:
Reactant = 1
Product = 1
The number of atoms of Cl:
Reactant = 1
Product = 1
The number of atoms of O:
Reactant = 3
Product = 2
The number of atoms of products and reactant is not equal, Thus, the reaction did not follow the conservation of mass.
(D) [tex]\rm H_2O\;+\;CO_2\;\rightarrow\;H_2CO_3[/tex]
The number of atoms of H:
Reactant = 2
Product = 2
The number of atoms of O:
Reactant = 3
Product = 3
The number of atoms of C:
Reactant = 1
Product = 1
The number of atoms of products and reactant is equal, Thus, the reaction follows the conservation of mass.
The chemical reaction that follows the conservation of mass has been the formation of hydrogen carbonate. Thus, option D is correct.
For more information about the chemical reaction, refer to the link:
https://brainly.com/question/13383562?
wich represents a element
carbon monoxide: CO
water:H2O
salt:NaCl
copper: Cu
Pleaseee help me on this
The amount of matter in an object is its ____
weight
mass
volume
density
How much sunlight is there in the transition zone. For science.
Answer:
Transition zone of the sun
Explanation:
Transition Region - The transition region is a very narrow (60 miles / 100 km) layer between the chromosphere and the corona where the temperature rises abruptly from about 8000 to about 500,000 K (14,000 to 900,000 degrees F, 7700 to 500,000 degrees C).
Compound I --> 75g total, 52.46g iron, 22.54g oxygen, Compound 2 --> 56g total, 43.53g iron, 12.47g oxygen
PLEASE HELP
Answer:
1*6
Explanation:
What are the particles that are found in the nucleus of an atom
Answer:
Protons and Neutrons
Explanation:
sketch a heating curve for water at 101kPa
using the information from the phase diagram. Label the melting point and
boiling point temperatures on your heating curve
Answer:
Please find attached a sketch of the heating curve of water at atmospheric pressure ( approximately 101 kPa) as traced from an online source
Explanation:
Given that the pressure at 101 kPa is approximately 1 atmosphere, we have;
The melting point and the boiling point occurs at approximately 0°C and approximately 100°C, respectively;
The melting point and the boiling point experience latent heat, therefore that temperature remains the same, though heat is continuously added
Also, given that the latent heat of vaporization (22.6 × 10⁵ J/kg) is approximately 7 times the latent heat of fusion is (3.33 × 10⁵ J/kg), the length of the plateau representing evaporation would be approximately 7 times longer than the length representing fusion.
The heating curve obtained from an online source for water at atmospheric pressure, is presented in the attached sketch.
What is the correct electron-dot formula for Sulfur?
.......................................................
One tank of gold fish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six week study. The fish's weight is recorded daily. All tanks were of the same size and shape. IV: DV: Control Group:
The question is incomplete, the complete question is;
One tank of goldfish is feed the normal amount which is once a day, a second tank is fed twice a day, and a third tank is fed four times a day during a 6 week study. The fishes' body fat is recorded daily.
Independent Variable-
Dependent Variable-
Constants
Control Group-
Answer:
A) The amount of food the gold fish receives
B) Body fat of the gold fish
C) -Type of fish used in the study (gold fish)
Time period within which the fishes were fed (Six week period)
Shape and size of tank
D) group of gold fish fed the normal amount
Explanation:
The purpose of the study is to determined the impact of amount of feed on the body fat of gold fish. Hence, the amount of feed is the independent variable while the body fat of the feed is the dependent variable.
The control group receives the normal amount of feed (once a day). The fishes are all gold fish, fed within a six week period. All the tanks were of the same shape and size. These are the constants in the study.
According to the big bang theory, what was distributed in every direction as the universe expanded?
Answer: la masa porque a lo largo del tiempo se fueron creando planetas por todo el universo
Explanation:
How many electron domains does IF4+ have?
What challenges do scientists face in studying the Sun?
The challenges do scientists face in studying the sun is that due to high amount of heat, it is impossible to see sun.
What is sun?Sun is a ball of hydrogen and helium gases which may produce large amount of heat as a result of nuclear fusion reaction.
High amount of heat is produced in the sun so it is not possible to see the sun from the normal eyes. Scientist uses telescope with mant filters to see a clear picture of the sun. Scientists are also not able to go near to the sun as produced heat is that much of power as they burn any object.
Hence above challenges are scientist face.
To know more about sun, visit the below link:
https://brainly.com/question/910950
Why is governmental funding of research important?
A. The government makes sure all scientists get the same amount of
money.
B. The government grants funding only to scientists whose research
won't harm people.
C. Scientists work for the government, which is where they get their
money from.
D. The government determines what is right and wrong for everyone.
Answer:
D. The government determines what is right & wrong for everyone
Explanation:
What is the name of the ionic compound CaCN?
Answer:
Calcium cyanamide
Explanation:
I think it has to be calcium cyanide, because of the cyanamide ion (CN).
Directions: The diagram below shows Earth's orbit around the Sun. Use the diagram and
your knowledge of science to answer any questions that follow.
SL
SK
2
Expectation: 8.7(A)
At what position is it spring in the Northern Hemisphere?
Position
(6) Position K
© Position L
D Position M
Answer:
i think its k.
Explanation:
position k im sure
Can someone help me balance these out?
Answer:
2 C7H6O2 + 15 O2 --> 14 CO2 + 6 H2O
Explanation:
please help if u can ty..
Answer:
a) [tex]BaF_{2}[/tex]
b) [tex]SnCl_{4}[/tex]
c) [tex]Cr_{2}O_{3}[/tex]
d) [tex]FeO[/tex]
e) [tex]Li_{3} P[/tex]
Explanation:
The charges of the ions have to be 0, so they balance.
a) [tex]Ba^{2+}[/tex] has the charge of +2 and [tex]F^{-}[/tex] has the charge of -1. So its [tex]0=(+2)+(-1)*2[/tex]. That means you need one [tex]Ba^{2+}[/tex] and two [tex]F^{-}[/tex] to balance the equation. -> [tex]BaF_{2}[/tex]
b) [tex]Sn^{4+}[/tex] has the charge of +4 and [tex]Cl^{-}[/tex] has the charge of -1. So its [tex]0=(+4)+(-1)*4[/tex]. That means you need one [tex]Sn^{4+}[/tex] and four [tex]Cl^{-}[/tex] to balance the equation. -> [tex]SnCl_{4}[/tex]
c) [tex]Cr^{3+}[/tex] has the charge of +3 and [tex]O^{2-}[/tex] has the charge of -2. So its [tex]0=(+3)*2+(-2)*3[/tex]. That means you need two [tex]Cr^{3+}[/tex] and three [tex]O^{2-}[/tex] to balance the equation. -> [tex]Cr_{2}O_{3}[/tex]
d) [tex]Fe^{2+}[/tex] has the charge of +2 and [tex]O^{2-}[/tex]has the charge of -2. So its [tex]0=(+2)+(-2)[/tex]. That means you need one [tex]Fe^{2+}[/tex] and one [tex]O^{2-}[/tex] to balance the equation. -> [tex]FeO[/tex]
e) [tex]Li^{+}[/tex] has the charge of +1 and [tex]P^{3-}[/tex]has the charge of -3. So its [tex]0=(+1)*3+(-3)[/tex]. That means you need three [tex]Li^{+}[/tex] and one [tex]P^{3-}[/tex] to balance the equation. -> [tex]Li_{3} P[/tex]
What element has 80 protons, 81 neutrons, 79 electrons?
Answer:
The element will be [tex]^{161}_{80}X[/tex]
Explanation:
Given that,
Number of proton = 80
Number of neutron = 81
Number of electron = 79
We know that,
The atomic number is equal to the number of proton.
So, the atomic number is 80.
According to atomic number,
The element will be mercury.
We need to calculate the atomic mass
Using formula of atomic mass
[tex]atomic\ mass=atomic\ number+number\ of\ neutron[/tex]
Put the value into the formula
[tex]atomic\ mass=80+81[/tex]
[tex]atomic\ mass=161[/tex]
We need to find the element
Using atomic mass and atomic number
[tex]atomic\ mass\ number A=161[/tex]
[tex]atomic\ number Z=80[/tex]
So, the element will be
[tex]^{A}_{Z}X[/tex]
Put the value of A and Z
Hence, The element will be [tex]^{161}_{80}X[/tex]
What is the density of an objects with a volume of 4.3 mL and a mass of 8.32g
Answer:
The answer is 1.93 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume}\\[/tex]
From the question
mass = 8.32 g
volume = 4.3 mL
So we have
[tex]density = \frac{8.32}{4.3} \\ = 1.934883720...[/tex]
We have the final answer as
1.93 g/mLHope this helps you
please help if you can. thank you.
A gold cube is 150.00 mm long, 10.00 cm wide, and 0.95 m thick. If gold has a density of 19.3g/cm3. Calculate the mass of the gold cube.
Help?
Answer:
V = l * w * h
V = 150.00 mm x 1cm/10 mm x 10.00 cm x 0.95 m x 100 cm/1 m = 1.4 x 104 cm3 D = M/V
M = D * V = 19.3 g/cm^3 * 1.4 * 104 cm^3 = 2.7 x 10^5 g = 270000 grams
The isotope Np-238 has a half life of 2.0 days if 96 grams of it were present on Monday how much will remain six days later
Answer:
12.02 g
Explanation:
From the question given above, the following data were obtained:
Half life (t½) = 2 days
Original amount (N₀) = 96 g
Time (t) = 6 days
Amount remaining (N) =..?
Next, we shall determine the rate of disintegration of the isotope. This can be obtained as follow:
Half life (t½) = 2 days
Decay constant (K) =?
K = 0.693 / t½
K = 0.693 / 2
K = 0.3465 /day
Therefore, the rate of disintegration of the isotope is 0.3465 /day.
Finally, we shall determine the amount of the isotope remaining after 6 days as follow:
Original amount (N₀) = 96 g
Time (t) = 6 days
Decay constant (K) = 0.3465 /day.
Amount remaining (N) =.?
Log (N₀/N) = kt / 2.303
Log (96/N) = (0.3465 × 6) / 2.303
Log (96/N) = 2.079/2.303
Log (96/N) = 0.9027
Take the anti log of 0.9027
96/N = anti log (0.9027)
96/N = 7.99
Cross multiply
96 = N × 7.99
Divide both side by 7.99
N = 96 /7.99
N = 12.02 g
Therefore, the amount of the isotope remaining after 6 days is 12.02 g
Which of the following is the correct Lewis Dot Structure for N2?
PHOTO ABOVE
please help I got it wrong so is not D
The correct Lewis Dot Structure for Nitrogen is structure C. Therefore, option C is correct.
What is lewis dot structure ?The valence shell electrons in a molecule are depicted in an extremely simplified manner by a Lewis Structure. It is used to demonstrate how the electrons in a molecule are positioned around particular atoms.
Gilbert N. Lewis, who first described it in his 1916 article The Atom and the Molecule, gave the Lewis structure its name. Lewis structures add lines between atoms to represent shared pairs in a chemical bond, extending the idea of the electron dot diagram.
In Nitrogen molecule, every nitrogen atom has five valence electrons and there is a triple bond between the two nitrogen atoms. Thus, the correct lewis dot structure is; :N⋮⋮N: .
Thus, option C is correct.
To learn more about the lewis dot structure, follow the link;
https://brainly.com/question/4144781
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