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A student places three ice cubes in a beaker and allows them to partially melt. If she measures the temperature of the water in the beaker, what will she most likely observe? Explain your answer.
**Check for proof photos at the bottom.**
**Answers are in bold.**
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A student places three ice cubes in a beaker and allows them to partially melt. If she measures the temperature of the water in the beaker, what will she most likely observe? Explain your answer.
She will see that the temperature of the water is 0 degrees Celsius and it stays at that temperature until all the ice cubes completely melt.
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Use the table on the right to calculate each required quantity. Record values to 3 significant digits.
First answer: 35.8 kJ
Second answer: 871 g
Third answer: Fe
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An iron sphere with a mass of 75.00 g is heated to a temperature of 385.0°C. It is then placed in a beaker containing 150.0 g H2O at 100.0°C.
First answer: 339 kJ
Second answer: 9.02 kJ
Third answer: No
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A sample of water has a mass of 100.0 g. Calculate the amount of heat required to change the sample from ice at –45.00°C to water vapor at 175.0°C. Relevant constant values are given to the right.
First answer: 325 kJ
Second answer: boiling the water
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Identify the correct description for each part labeled on the diagram.
A: ✔ heating solid
B: ✔ melting
C: ✔ heating liquid
D: ✔ boiling
E: ✔ heating gas
F: ✔ melting point
G: ✔ boiling point
Where are the particles closest together?
✔ A
Explanation:When ice partially melts, the surrounding water remains at 0° Celsius. This is because ice melting only involves the water molecules overcoming intermolecular forces, or forces holding molecules together. The water molecules themselves aren't increasing in kinetic energy when turning into liquid. Since temperature measures kinetic energy, the temperature in this case, remains at 0°.
To find how much energy it takes to cause a phase change in a substance, you must find the number of moles, and determine whether to use ΔHvap and ΔHfus. ΔHvap is used to show how much energy is involved in evaporation and condensation, and ΔHfus is the same but used for melting and freezing. To find number of moles of a given substance, use the formula: mass of given substance divided by atomic mass. Both numbers have to use the same mass unit. Then, multiply number of moles by ΔHvap or ΔHfus to get kJ.
In a heating curve graph, the flat lines represent no change in energy, or the phase changes. The steep lines are change in energy, which are either heating or cooling. The bottom line is a heating/cooling solid. A heating/cooling solid is the coldest phase, which is why the line is at the bottom.
Here are photos of Edge to make things easier.
. 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.
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.
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.
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:
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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
A boy inherited genes that would ordinarily allow him to grow tall.his growth is stunted as a result of poor nutrition.this is an example of
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
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.
You decide to race your buddy after school. The race starts at the 10 yard line and ends at the 50 yard line. How long was the race
Answer:
Long of the race = 40 yard
Explanation:
The long of the race is measured from the distance in the beginning (10 yard line) to the distance and the end of the race (50 yard line). The distance of the race is the difference between both lines. That is:
Long of the race = 50 yard - 10 yard
Long of the race = 40 yard
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.
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
Acid-base neutralization means having a pH of 7. true or false ?
Answer:
True
Explanation:
A pH of 7 is greater than basic but lesser than acidic. Therefore, it's neutral
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
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
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
can someone do my watershed project ill give brainly and 80 points
You have 11.27 moles of Cl2 gas. How many moles of NaBr do you need to completely undergo this reaction?
Answer:
22.54 moles of NaBr are needed
Explanation:
The reaction of Cl2 with NaBr occurs as follows:
Cl2 + 2NaBr → 2NaCl + Br2
Where 1 mole of Cl2 requires 2 moles of NaBr for a complete reaction
As in the problem, we have 11.27 moles of Cl2, the moles of NaBr required are:
11.27mol Cl2 * (2mol NaBr / 1mol Br2) =
22.54 moles of NaBr are neededBalance 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)
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:
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
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 ^^
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
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:
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
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!
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
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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Please help me. I am doing a test and, I don’t know this one.
Answer: 22
Explanation: