Answer:
4.84 m
Explanation:
To solve this problem we need Frezing point depression.
Formula is: ΔT = Kf . m . i
ΔT = 18°C
This is data. ΔT is the difference, Freezing T° of pure solute - Freezing T° of solution.
Kf = 1.86 °C/m
m = molality. Our unknown.
i = Ions dissolved in solution, also called Van't Hoff factor.
NaCl → Na⁻ + Cl⁻
Sodium chloride can produce 2 moles of ions.
We replace data: 18°C = 1.86 °C/m . m . 2
18°C / (1.86 °C/m) . 2 = m
molality = 4.84
hlight
How are rocks weathered as in this example seen here?
ame
aining
22:01
Tools
A)
The rocks change their composition.
B)
The rocks are being chemically weathered by the water.
Freezing and thawing of water breaks the rocks into pieces.
D)
Hot lava is pushing on the rock and breaking it into pieces.
Answer:
B). The rocks are being chemically weathered by the water.
Explanation:
Because the water is slowly destroying the rock
Calculate the pH of 1.0 X 10^-4 M HNO3
Answer:
pH = 4
Explanation:
Given that,
The concentration of [H⁺] is [tex]10^{-4}\ M[/tex]
We need to find the pH of the solution. We know that,
[tex]pH=-log[H^+][/tex]
Also,
HNO3 → H+ + NO-3
Put all the values,
[tex]pH=-log[1\times 10^{-4}]\\\\pH=4[/tex]
So, the pH of the solution is equal to 4.
please answer cansend to me
A chemist prepares a solution of silver perchlorate (Agcio) by measuring out 0.91 kg of silver perchlorate into a 400 ml. volumetric flask and filling the flask
to the mark with water
Calculate the concentration in mol L of the chemist's silver perchlorate solution. Be sure your answer has the correct number of significant digits.
Answer:
오빠nsuensojee9ejenheie
I have prepared a caffeine stock solution of 0.075 M. What volume should we mix with
distilled water in order to reach a standard solution of 0.0015 M and a final volume of 10
mL?
a) 0.2 mL
b) 112.5 mL
c) 50 mL
d) 2 mL
PLEASE HELP!
No Links!
I will award brainliest to the first person to answer
Answer:
I think 50 ml but I am not sure
sorry
What are the columns on the periodic table called?
(2.5 Points)
Answer:
A group is a column of elements in the periodic table of the chemical elements.
So, the columns on the periodic table are called groups.
The galvanic cell illustrated above generates a potential of +1.10V. For the construction of a second galvanic cell (not shown), only one modification was made: the Cu electrode has double the mass of the Cu electrode in the first cell. Which of the following correctly compares the initial E° for the second cell to that of first cell at 298K, and why?
Answer:
The initial E° for the second cell is the same as for the first cell.
Explanation:
Because the overall chemical reaction that occurs in the cell does not change.
The first galvanic cell generated the cell potential of +1.10 V. The second galvanic cell generates the same cell potential because the overall cell reaction remains the same.
What is a galvanic cell?The galvanic cell is given as the electrochemical cell that generates the exchange of chemical and electrical energy.
The cell potential is described as the rate of reaction with the difference in the potential of the cathode and the anode.
The reduction and the oxidation potential are governed by the number of electrons transferred in the chemical reaction.
In the second galvanic cell, the number of electrons transferred from the copper electrode will be equivalent to the first electrode, as the chemical reaction is the same. Thus, the cell potential of the second galvanic cell will be the same as the first cell.
Learn more about galvanic cell, here:
https://brainly.com/question/25606438
The term “ sea of electrons “ refers to
Answer:
Explanation:
Basically in metallic bonds, valence electrons are not localied which means they can freely move from one atom to another. Thus, they move in "sea of electrons" because in a sea water or waves are freely moving without any localization.
Hope that helps.
Conversion of solid state to liquid state is called fusion; what is meant by latent heat of fusion?
Answer:
Explanation:
Latent heat of fusion, also known as enthalpy of fusion, is the amount of energy that must be supplied to a solid substance (typically in the form of heat) in order to trigger a change in its physical state and convert it into a liquid (when the pressure of the environment is kept constant). For example, the latent heat of fusion of one kilogram of water, which is the amount of heat energy that must be supplied to convert 1 kg of ice without changing the temperature of the environment (which is kept at zero degrees celsius) is 333.55 kilojoules
The latent heat of fusion of a substance also accounts for the energy required to accommodate any increase in the volume of the substance post the change of its physical state. The temperature at which the substance undergoes the phase transition is called the melting point of the substance. Unless specified to be otherwise, the pressure of the environment (when expressing the latent heat of fusion of a substance) is always assumed to be 1 atmosphere of pressure (which is roughly equal to 101.325 kilopascals).
A fire is an example of an exothermic reaction. Which of the following best
supports that statement?
A. The fire is creating energy.
B. The fire is releasing energy.
C. The fire is capturing energy.
D. The fire is destroying energy.
Answer: B. Fire is releasing energy
Explanation:
. A scientist placed a sample of lithium into a container of water. The scientist observed the lithium floating and making a buzzing sound as gas bubbles were forming around it. Which conclusion is BEST supported by this observation
Answer: The conclusion that best support the observation is that (A CHEMICAL CHANGE took place).
Explanation:
A chemical reaction is defined as the process by which two or more substances, which are often referred to as REACTANTS, combine through bond formation or dissociation of bonds to form new PRODUCTS. In this type of reaction, a CHEMICAL CHANGE occurred because a new substance is formed as a result of the chemical reaction that took place.
There are different characteristics of a reaction which shows that a chemical change has occurred, these includes:
--> Color Change
--> Production of an odor
--> Change of Temperature
--> Evolution of a gas (formation of bubbles)
-- Precipitate (formation of a solid)
From the chemical reaction in the given question, Lithium metals reacts slowly with water to form a colourless solution of lithium hydroxide (LiOH) and hydrogen gas (H2). Here we observe that the buzzing sound of formed gas bubbles shows that a gas was given off. Therefore in conclusion, a CHEMICAL CHANGE took place.
Balance this chemical equation
Ca(OH)2 + HCl ---> CaCl2 + H2O
Answer:
The balance equation of Ca(OH)2 + HCl ---> CaCl2 + H2O
is
Ca(OH)2(s) + 2HCl(aq) ---> CaCl2(aq) +2H2O (l) (balanced equation)
2KOH + H2SO4 → K2SO4 + 2H20
What mass of water would be produced if 19.6g of KOH were reacted?
19.6 × ( 1 mol KOH / 56 grams KOH )
= 0.35 mol KOH
_________________________________
0.35 mol KOH ×( 2 mol H2O / 2 mol KOH )
= 0.35 mol H20
_________________________________
0.35 mol H2O × ( 18 g H2O / 1 mol H2O )
= 6.3 grams H2O
A hot metal is placed in 100.0 g sample of water and it causes the temperature of the water to increase from 25 C to 27 C. How many joules of energy did the water absorb from the metal?
Answer: [tex]836.8\ J[/tex]
Explanation:
Given
Mass of water in the sample is [tex]m=100\ g[/tex]
Temperature changes from [tex]25^{\circ}C[/tex] to [tex]27^{\circ}C[/tex]
Change in temperature is [tex]\Delta T=27-25=2^{\circ}C\ \text{or}\ 2\ K[/tex]
We know, specific heat of water is [tex]c=4.184\ J/g-K[/tex]
Heat absorbed is given by
[tex]\Rightarrow Q=mc\Delta T\\\Rightarrow Q=100\times 4.184\times 2\\\Rightarrow Q=836.8\ J[/tex]
Thus, water absorbs [tex]836.8\ J[/tex] of heat from hot plate.
11
1. If 325 grams of sodium nitrate are added to water to make the total solution volume 5.5 L,
what is the concentration (molarity) of this solution?
Answer: 0.695 mol/L
Explanation:
To find the final concentration of the solution, we must first identify the moles of the solute (NaNO₃):
moles = mass ÷ molar mass
∴ moles of NaNO₃ = 325 g ÷ 84.995 g/mol
= 3.824 mol
Now, since the final volume is 5.5 L and this volume contains the 3.824 moles of NaNO₃,
then the molarity of the solution = 3.824 mol ÷ 5.5 L
= 0.695 mol/L
What is the chemical formula of diphosphorus monoxide?
Answer:
The chemical formula of diphosphorus monoxide is OP2.
I'm not sure if this is correct, but hope it helps! :)
Your silver watchband has a mass of 326 g. How many moles of Ag do you have?
Answer:
3.02 moles
Explanation:
Converted using mole calculator.
Answer:
[tex]\boxed {\boxed {\sf 3.02 \ mol \ Ag}}[/tex]
Explanation:
We want to convert grams of silver to moles of silver. We can do this in 2 steps.
1. Convert Grams to MolesWe can convert grams to moles using the molar mass. It tells us the mass of 1 mole of a substance.
This is a value found on the Periodic Table. It is the same value as the atomic mass, but the units are grams per mole (g/mol) instead of atomic mass units (amu). Look up silver's molar mass.
Ag: 107.868 g/molLet's make a ratio using the molar mass.
[tex]\frac{107.868 \ g\ Ag}{ 1 \ mol \ Ag}[/tex]
Since we are converting 326 grams to moles, we multiply by that value.
[tex]326 \ g\ Ag*\frac{107.868 \ g\ Ag}{ 1 \ mol \ Ag}[/tex]
Flip the ratio so the units of grams of silver cancel.
[tex]326 \ g\ Ag*\frac{ 1 \ mol \ Ag}{107.868 \ g\ Ag}[/tex]
[tex]326*\frac{ 1 \ mol \ Ag}{107.868}[/tex]
[tex]\frac{ 326}{107.868} \ mol \ Ag[/tex]
[tex]3.02221233359 \ mol \ Ag[/tex]
2. RoundThe original measurement of mass (326 grams) has 3 significant figures, so our answer must have the same.
For the number we found, that is the hundredth place. The 2 in the thousandth place (3.02221233359) tells us to leave the 2 in the hundredth place.
[tex]3.02 \ mol \ Ag[/tex]
A silver watchband with a mass of 326 grams is equal to 3.02 moles of silver.
Force is measured in this unit
a. grams
b. m/s
c. newtons
d. m/s/s
Answer:
Force is measured in Newtons, which are units that equal 1 kg * m/sec 2. Force is measured in Newtons, N. Mass is measured in kilograms, kg. The unit that is used to measure force in the SI system of units is the Newton.
Answer is Newtons because I looked it up
A 600-ml solution of alcohol contains 350 mL of water. What
is the mass percent of alcohol?
answer options:
41.7 % alcohol solution
71.4 % alcohol solution
2.5 % alcohol solution
40% alcohol solution
Why does the rate of the forward reaction increase when the surface area of a reactant is increased
?
When the surface area increases, the concentration of the substance increases, which reduces
the number of effective collisions.
When the surface area increases, the temperature of the system increases, which in turn
increases the number of effective collisions.
When the surface area increases, the density of the substance increases, which increases the
number of collisions.
When the surface area increases, the number of particle collisions increases, which in turn
increases the number of effective collisions.
HELP PLEASE!!!!!
What is the molarity of a solution prepared by dissolving 30.0 grams of NaOH in enough water to make a solution with a total volume of 2.40 liters? (5 points)
0.150 M NaOH
0.218 M NaOH
0.313 M NaOH
0.462 M NaOH
Answer:
0.313 M NaOH
Explanation:
Got it right on the test.
Taking into account the definition of molarity, the molarity of the solution is 0.313 M.
Definition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]molarity=\frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
This caseIn this case, you know:
number of moles= 30 grams×[tex]\frac{1 mole}{40 grams}[/tex]= 0.75 moles (being 40 [tex]\frac{grams}{mole}[/tex] the molar mass of NaOH)volume= 2.40 LReplacing in the definition of molarity:
[tex]molarity=\frac{0.75 moles}{2.40 L}[/tex]
Solving:
molarity= 0.313 M
Finally, the molarity of the solution is 0.313 M.
Learn more about molarity:
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#SPJ2
Why does Watney get left behind on Mars?
Answer:
I think it's because he was presumed dead after a storm, or like a problem with his suit
Explanation: I think it was because somebody thought he was dead in the storm? And the remaining of the crew were forced to leave him behind thinking he was dead on mars.
I might be right, might not ^^
Someone help pleaseeee I will give brainliest
Answer:
2-Methylhexane
Because Ethylexane does not have hydrogen molecules neither,also it only has 2 options but they're just repeated
list the universities of nepal and explain about one of them.
Answer:
Tribhuvan University is a university in Tribhuvan, Nepal. Tribhuvan University (TU) is a pioneering higher education institution in Nepal, having been founded in 1959. ......
Pokhara University... Kathmandu University...
Purbanchal University is located in Purbanchal, India.
Lumbini Bauddha University (LBU) is a university in Lumbini, Nepal...
Nepal Sanskrit University is a university dedicated to the study of Sanskrit in Nepal.
Midwestern University is a public university in the Midwest...
Nepal Open University is a public university in Nepal.
Explanation:
Fossil fuels are made up of
A. aromatic hydrocarbons
B. acids
C. hydrocarbons
D. optical isomers
Answer:
I think its option C
Explanation:
Answer:
C. Hydrocarbons
Explanation:
I think it is C
Please help me. I am doing a test and, I don’t know this one.
Answer: 22
Explanation:
can someone do my watershed project ill give brainly and 80 points
2.
The atoms that make up nitrogen gas...
N2
A share two covalent bonds.
B. have a definite shape.
1
C. share a pair of neutrons.
D. have two free electrons.
Answer:
A they share two covalent bonds
Which of the following are acid formulas? (Choose 2)
NH3
CH3OH
NaOH
HNO3
H2SO4
CH4
Answer:
HNO3 & H2SO4
Explanation:
HNO3 is Nitric acid and H2SO4 is Sulphuric acid
What is the pH of a solution with a 3.2 x 10-5 M hydronium ion concentration? (5 points)
4.3
11
4.5
12.
Answer: 4.5
Explanation: Got it right on the exam. Hope this helps!