Answer:
Barium and chlorine
Explanation:
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When a student dissolves 2.50 g of LiCl in 100.0 mL of water (100.0 g) the temperature rises from 24.0 oC to 29.11oC. What is ∆H in KJ/mol for the dissolution of LiCl in water? Make sure you include the correct sign for ∆H and units (with a space between number and unit)
Answer:
[tex]36.273\ \text{kJ/mol}[/tex]
Explanation:
m = Mass of LiCl = 2.5 g
M = Molar mass of LiCl = 42.394 g/mol
c = Specific heat of water = [tex]4.186\ \text{J/g}^{\circ}\text{C}[/tex]
[tex]\Delta T[/tex] = Change in temperature = [tex]29.11-24=5.11\ ^{\circ}\text{C}[/tex]
[tex]m_w[/tex] = Mass of water = [tex]\rho V=1\times 100=100\ \text{g}[/tex]
Number of moles
[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{2.5}{42.394}\\\Rightarrow n=0.05897\ \text{mol}[/tex]
Heat is given by
[tex]Q=m_wc\Delta T\\\Rightarrow Q=100\times 4.186\times 5.11\\\Rightarrow Q=2139.046\ \text{J}[/tex]
Enthalpy is given by
[tex]\Delta H=\dfrac{Q}{n}\\\Rightarrow \Delta H=\dfrac{2139.046}{0.05897}\\\Rightarrow \Delta H=36273.46\ \text{J/mol}=36.273\ \text{kJ/mol}[/tex]
The enthalpy for the dissolution is [tex]36.273\ \text{kJ/mol}[/tex].
How are monosaccharides and polysaccharides structurally different? *NO PLAGIARISM PLS*
Explanation:
Monosaccharides are simple carbohydrates that cannot be further hydrolyzed to simpler carbohydrates. They contain between three and six carbon atoms per molecule.
Polysaccharides are complex carbohydrates . They are condensation polymers derived from very long chains of monosaccharide units.
Structurally, polysaccharides are made up of repeating units of monosaccharides.
Who arranged the elements according to atomic mass and used the arrangement to predict the properties of missing element?
Answer:
Dmitri Mendeleev
Explanation:
Dmitri Mendeleev a Russian Chemist arranged elements on the periodic table according to their atomic mass. He used this arrangement to predict some of the properties of the missing element.
Dmitri Mendeleev around 1869 described the periodic table. The table was based on the periodic law which states that "chemical properties of elements are a periodic function of their atomic weights". In the Mendeleev table, elements are arranged by atomic weights with recurring properties in a periodic manner.what is copper in chemisry
Answer: Copper in Chemisry is an chemical element, a reddish, extremely ductile metal of Group 11 (Ib) of the periodic table that is an unusually good conductor of electricity and heat. Copper is found in the free metallic state in nature.
Explanation:
Can you please help me it is urgent! A student is given a sample of an unknown liquid to test in the laboratory. The student thinks that the liquid is water. Which of the following properties of the sample is most helpful to determine if the liquid is water?
(A) color of the liquid
(B) mass of the liquid
(C) the volume of the liquid
(D) the boiling point of the liquid
Answer:
The answer is Boling Point
Explanation:
The properties of the sample which is most helpful to determine if the liquid is water is (D) . the boiling point of the liquid
What is Boiling Point ?
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
The boiling point of a liquid varies depending upon the surrounding environmental pressure
Substances at different states usually possess certain properties that distinguishes them. For example, in this case involving a student who was given a sample of an unknown liquid to test in the laboratory, he thinks that the unknown liquid is water.
Specific properties of the unknown liquid can be used to identify whether it is water or not.
One property that can be used to ascertain whether or not it is water is the boiling point of the liquid. This is because specific liquids have specific boiling point. So if the unknown liquid has a boiling point of 100°C, then it can be ascertained to be water.
Therefore, The properties of the sample which is most helpful to determine if the liquid is water is (D) . the boiling point of the liquid
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10 examples of semi-metals
Answer:
boron.silicon.germanium.arsenic.antimony.tellurium.polonium.A wave with a higher frequency has a longer wavelength
TRUE
FALSE
Answer:
FalseA wave with a higher frequency have a shorter wavelength, the higher the sound it, the closer the arcs of the wavelength are, the faster the sound is, the shorter they are.
According to scied.ucar.edu ~ "The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength. Light waves have very, very short wavelengths."
Hope this helps
Explanation:
May I have brainliest please? :)
A wave with a higher frequency has a longer wavelength is a false.
Relation of frequency, energy and wavelengthA wave with a higher frequency has a longer wavelength is a false statement because shorter wavelength have higher frequency and also higher energy.
We know that longer wavelength of a wave having shorter frequency and shorter energy while on the other hand, the shorter wavelength of a wave having higher frequency and higher energy so we can conclude that the statement is false.
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WILL GIVE BRAINLIEST
Answer:
1 Mole
Explanation:
1 mole is equal to 1 moles NH4, or 18.03846 grams.
i dont understand this i cant think :These ions have the same stable electron configuration as the noble gas helium. All Group 1 atoms can lose one electron to form positively charged ions. ... Elements in Groups 15,16 and 17, find it easier to gain electrons than lose them.
Answer:
Li atoms readily give up one electron to form positively charged, Li+ ions. These ions have the same stable electron configuration as the noble gas helium. All Group 1 atoms can lose one electron to form positively charged ions.
Explanation:
I DON'T KNOW IF THIS IS THE RIGHT ANSWER BUT I'M TRYING TO JUST ANSWER.
Answer:
Explanation:
-We know that an atom is table if they have 8 valence electrons (like noble gases, they are stable)
-Group 1 atoms only has 1 valence electron, in order to become stable, they are desperately wanted to lose that one valence electron to become stable.
-While group 15 has 5 electrons, it is easier for them to gain 3 electrons to become 8 electrons than losing all 5 electrons.
-the same thing for group 16 has 6 valence electrons and 17 has 7 electrons. It is easier for them to gain 2 and 1 more valence electrons to become stable.
Hope this helps!
how do you think the number of electrons affects an element’s reactivity?
Write a paragraph explaining what would happen if liquids A,B 3,C, and D were added to the graduated cylinder. Describe how the layers of the density column would be arranged (the order they would be in). Finally, predict where an object with a density of 1.07 g/cm^ 3 would stop in the column. Justify your reasoning with quantitative data (your density calculations).
which statement is true of a rock layer that had another rock layer deposited on top of it?
Answer:
second rock...I know it
what is the formula for
a. mercury (ll) nitride
b. Cobalt (ll) bromide
Answer:
a Hg(NO3)2
b CoBr2,CoBr2·6H2O,CoBr2·2H2O
Explanation:
Which statement best explains why an object appears green in sunlight?
A- The object absorbs most white light and refracts most green light.
B- The object refracts most white light and absorbs most green light.
C- More green light is absorbed while more red and blue light is reflected.
D- More green light is reflected while more red and blue light is absorbed.
Answer:
b
Explanation:
Describe the relationship between the solubility rate of a gas and temperature.
25 points
Answer:
as temperature increases, solubility of gas decrease
i need help with scientific notation. this is the decimal notation form help.
Answer:
1.23345*10^11
5.768*10^(-5)
3.456*10^(-2)
2.28*10^9
8.0970*10^4
Explanation:
You just need to count the number of zeros and move the values backward and forward to get the scientific notation.
In the reaction C + 02 - CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction? O 18 g O 54 g O 72 g 0 90 g
Mass of oxygen : 54 g
Further explanationConservation of mass applies to a closed system, where the masses before and after the reaction are the same
Reaction
[tex]\tt C+O_2\rightarrow CO_2[/tex]
mass before reaction = mass after reaction
mass C + mass O₂= mass CO₂
[tex]\tt 18~g+mass~O_2=72~g\\\\mass~O_2=72-18=\boxed{\bold{54~g}}[/tex]
What molecule contains a carbon atom with trigonal planar geometry?
Answer:
ethylene molecule. The molecule has trigonal planar geometry around its carbon atoms
Need Help!!Atomic Structure escape room. Enter 4 digit code(no spaces)
Answer:
9146
Explanation:
The letters are in the place of the number on the clock. A is in the place of 9, B is in the place of 1, and so on. I hope I was correct!
Answer:
9641
Explanation:
MOST of the elements in the periodic table are
A. liquids at room temperature
B. metals
C. metalloids
D. nonmetals
Answer:
B. metals
Explanation:
Most of the elements in the periodic table are classified as metals. They are usually solid at room temperature.
The first and second block of the periodic table are all metallic elements. Those in the d-block are all metals. Metals generally occupy the s and d -blocks. Non-metals and metalloids are found in the p-blocksHow can you separate sand, sugar and gravel
Answer:
Grating
Explanation:
I think you need to grate it
Answer: The sugar would dissolve in water. You could then pour off the solution and wash the remaining sand with a bit more water. Heat the water to evaporate it from the sugar, and the two are separate
Explanation:
In an atom, the number of neutrons is generally equal to or greater than the number of protons because....
Answer:
because the neutrons is always equal or greater there is never a less then in neutrons.
Explanation:hope this helped
Balance the following equation? Al + O2 - - - - - -) Al2O3
Answer:
4Al (s) + 3O₂ (g) → 2Al₂O₃
General Formulas and Concepts:
Chemistry - Reactions
Reaction PredictionBalancing RxN'sExplanation:
Step 1: Define RxN
Al (s) + O₂ (g) → Al₂O₃
Step 2: Balance RxN
4Al (s) + 3O₂ (g) → 2Al₂O₃
Need to balance the amount of oxygens on both sidesIf we balance the oxygens, the aluminums will also have to be rebalancedFind the celcius equivalent of 133 degrees Kelvin
Answer:
406 KExplanation:
To convert a temperature from degree Celsius to Kelvin add 273 to the value in degree Celsius
That's
K = 273 + °C
where
K is the temperature in Kelvin
°C is the temperature in degree Celsius
From the question we have
K = 273 + 133
We have the final answer as
406 KHope this helps you
A forklift applies a force of 2,000 N to raise a box 3 m.
How much work is done by the forklift in raising the
box?
If the force is applied to lift the box, then there is no work done as the displacement of the box is not in the same direction of the box.
However, if the force is being applied to move the box in the direction of the force, then the work done is:
Work = force x distance
Work = 1500 x 3
Work = 4,500 Joules
A forklift applies a force of 2,000 N to raise a box 3 m. The work is done by the forklift in raising the box is 6000 Joules.
What is force ?A force is an influence that has the power to alter an object's motion. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity, since it has both magnitude and direction.
Isaac Newton's three laws of motion, which are outlined in his Principia Mathematica, are frequently used to illustrate the concept of force (1687).
Contact forces and act at a distance forces are the two different types of forces. Your daily use of force is evident. Basically, push and pull are forces. You exert force on an object when you push against it or pull against it.
The force is applied to move the box in the direction of the force,
Then the work done is
Work = force x distance
Work = 2000 x 3
Work = 6000 Joules.
Thus, A forklift applies a force of 2,000 N to raise a box 3 m. The work is done by the forklift in raising the box is 6000 Joules.
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How many moles are 7.25 x 1023 formula units of Mgo ?
O A) 1.31 moles
OB) 1.33 moles
OC) 1.42 moles
D) 1.20 moles
O E) 1.27 moles
OF) 1.51 moles
OG) 1.29 moles
Answer:
The answer is option DExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{7.25 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{7.25}{6.02} \\ = 1.2043189368...[/tex]
We have the final answer as
1.20 molesHope this helps you
SnO₂ + 2H₂
+ 2 H2 → Sn + 2 H2O
Is it balanced or unbalanced
Answer:
I'm pretty sure it is unbalanced
The solid obtained at the neck of a funnel in sublimation is called....................?(mixture)
Answer:
Sublimate
Explanation:
The solid obtained at the neck of a funnel in sublimation is called the sublimate.
This substance is a solid.
Sublimation process is a phase change. In this process, a solid is directly changed to gas or gas changed to solid. Heat must be added to change the solid to gas and heat removed for the reverse process. Not all substances have this capability.Which equation shows how to calculate how many grams (g) of KOH would
be needed to fully react with 4 mol Mg(OH)2? The balanced reaction is:
MgCl2 + 2KOH → Mg(OH)2 + 2KCI
Answer:
A.
General Formulas and Concepts:
Chemistry - Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
Given: 4 mol Mg(OH)₂
RxN: MgCl₂ + 2KOH → Mg(OH)₂ + 2KCl
Step 2: Identify Conversions
Molar Mass of K - 39.10 g/mol
Molar mass of O - 16.00 g/mol
Molar mass of H - 1.01 g/mol
Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol
Step 3: Stoichiometry
[tex]4 \ mol \ Mg(OH)_2(\frac{2 \ mol \ KOH}{1 \ mol \ Mg(OH)_2} )(\frac{56.11 \ g \ KOH}{1 \ mol \ KOH} )[/tex]
Answer:
check the attachment/picture below!
Explanation:
I had just taken that quiz! :D
What percentage of the atmosphere is oxygen?
Answer:
21%
Explanation:
It's a mixture of different gases. The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.