Answer:
1) B. determining what data to collect
2) C. Heat samples of water and ethanol in two separate beakers using a Bunsen burner. Measure the temperatures at which the samples boil using a thermometer. Conduct several trials and record the average temperatures as the boiling points.
3) B. Heat energy overcomes the forces of attraction between the molecules of the substance, so the molecules can move more freely.
4). The addition of thermal energy causes the motion of water molecules to overcome electrostatic forces.
Explanation:
I think these are the answers, i'll confirm when I finish the test.
In an experiment it is known what quantity has to measured, thus the measurement of melting point has been determining what data to collect. Thus, Option B is correct.
To investigate the boiling point of water and ethanol, the samples has to boiled at constant parameters and the data has been collected with several trials. Thus, option C is correct.
Melting has been described as the change of the solid to the liquid state. With melting, there has been heat energy higher than the force of attraction allowing the molecules to move freely. Thus, option B is correct.
The boiling has been the change in the water at liquid state to the gaseous state. With boiling there is thermal energy capable of increasing the motion of water molecules overcoming electrostatic force.
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A quantity of 1.922 g of methanol (CH3OH) was burned in a constant-volume bomb calorimeter. Consequently, the temperature of the water rose by 4.20 Ce … lsius. If the heat capacity of the bomb plus water was 10.4 kJ/degree Celsius, calculate the molar heat of combustion of methanol
The formula for calculating the amount of energy or heat released is:
ΔH = C ΔT
where ΔH is heat of combustion, C is heat capacity, while ΔT is change in temperature
ΔH = 8.69 kJ / °C * (5.14°C)
ΔH = 44.67 kJ
Then we calculate the moles of CH3OH which has molar mass of 32.04 g/mol:
moles = 1.922 / 32.04 = 0.05999 mol
SO the molar heat of combustion is:
ΔHm = 44.67 kJ / 0.0599875 mol
ΔHm = 744.60 kJ / mol
A sample of N2O gas has a density of 2.95 g/L at 298 K. What must be the pressure of the gas?
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A sample of N2O gas has a density of 2.95 g/L at 298 K. What must be the pressure of the gas?[tex]\huge\fcolorbox{aqua}{lime}{Answer}[/tex]
P = 1203 mm Hg[tex]\huge{\underline{\underline{\boxed{\sf{\purple{Explanation}}}}}}[/tex]
#Given: -p = 2.85 g/LT = 298 K# Solution :-According to ideal gas equation -
➡PV = nRT
➡PV = (W/M)RT
➡PM = (W/V)RT
➡PM = PRT
➡P = pRT/M
➡P = 2.85 × 0.082 x 298 / 44
➡P = 1.583 atm
➡P = 1.583 × 760
➡P = 1203 mm Hg
Therefore, pressure of the gas. must be1203 mm of Hg.Hope this helps you:)
How is a mixture different from a compound?
Answer:
A compound is something like atoms coming together as a team, and a mixture is 2 or more substances mixing together.
Explanation:
How many valence electrons are there in the molecule CH3OCH2CH3.
Answer:
There are 27 Valence electrons : )
4+1+1+1+6+4+1+1+4+1+1+1 is 27
Explanation:
There are a total of [5×1]+[2×4]+[7]=21[5×1]+[2 × 4 ] + [ 7]=21 valence electrons
What is the pH when 30.0 ml of 0.005 M HF is mixed with 15.0 ml of 0.01 M NaOH?
Answer:
7.36
Explanation:
my teacher said that was the right answer
How much heat must be added to a 8.21 g sample of gold to increase its temperature from the tempe
75.3°C to 83.1°C? The specific heat of gold is 0.13 J/gºC
Answer:
Q= ms∆T
Where, m is mass of substance
S is specific heat
∆T is temperature change
As in question , m=8.21 ,s=0.13 ,∆T =6.2
So, Q = 8.21×0.13×6.2=6.61 J
What is the correct form of the equilibrium constant for the reaction of hydrogen and oxygen to form water? The equation is:
2H 2( g) + O 2( g) ⇌ H 2O( g)
Kc = ([H2O]/[O2] [H2])
Kc = ([H2O]/[O2] [H2]2)
Kc = ([H2O]/[O2] [H22])
Kc = ([H2O]2/[O2] [H22])
Kc = ([H2O]/[O2] [2H2])
Calculate the molar mass of magnesium chloride, CaCl 2.
Ca = 40.1g, Cl = 35.5g
Answer:
Ca = 40.1 g
Cl = 35.5
So CaCl240.1 + 35.5×2
40.1 + 71
111.1 g
Use the heat equation to find out how many joules of energy are needed
to raise the temperature of 67 grams of water form 20°C - 45°C. What is the
answer in kilojoules?
(specific heat of water is 4.2 J/gºC.)
Answer:
About 7.0 × 10³ J or 7.0 kJ
Explanation:
We want to determine the amount of energy needed to raise the temperature of 67 grams of water from 20°C to 45°C.
We can use the heat equation:
[tex]\displaystyle q = mC\Delta T[/tex]
Where C is the specific heat of water.
Substitute and evaluate:
[tex]\displaystyle \begin{aligned} q & = (67\text{ g})\left(\frac{4.2\text{ J}}{\text{g-$^\circ$C}}\right)\left(45^\circ \text{ C}- 20.^\circ\text{ C}\right) \\ \\ & = (67\text{ g})\left(\frac{4.2\text{ J}}{\text{g-$^\circ$C}}\right)(25^\circ \text{ C}) \\ \\ & = 7.0\times 10^3 \text{ J}\end{aligned}[/tex]
Recall that there are 1000 J in a kJ. Hence:
[tex]\displaystyle \begin{aligned} q & = 7.0\times 10^3 \text{ J} \cdot \frac{1\text{ kJ}}{1000\text{ J}} \\ \\ & = 7.0 \text{ kJ}\end{aligned}[/tex]
In conclusion, it will take about 7.0 × 10³ J or 7.0 kJ of energy to raise the temperature of 67 grams of water from 20 °C to 45 °C.
Why is the same type of nail used in all test tubes? in every experiment done to show how rusting works and in what conditions.
in test tube 1 iron nail gets both air and moisture which is required for rusting. ... in the test tube 3 iron nail is not rusted because of the calcium chloride which is moisture absorber. hence nail would not get moisture for the rusting.
How many teaspoons are equal to 1 mole of water if there is 0.23 teaspoon for every 1 g?
A. 0.46 teaspoon
B. 3.68 teaspoons
C. 4.14 teaspoons
D. 18 teaspoons
Answer:it's b hope that help
The molar mass of water is 18 g. Given that there are 0.23 teaspoon for every 1 g. Thus , for 18 g there would be 4.14 teaspoons.
What is one mole?Any substance that contains 6.022 × 10²³ number of atoms is called one mole of that substance. The mass of a compound or molecule containing these much atoms is called its molar mass.
Molar mass of water is 18 g. Thus, it means that one mole of water weighs 18 g. Given that for every 1 g of water there are 0.23 teaspoon. Thus, number of teaspoons for one mole or 18 g of water is:
number of teaspoons = 18 g × 0.23 /1 g
= 4.14 teaspoons.
Therefore, 4.14 teaspoons are required for one mole of water.
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Identify the unit that is used for atomic masses
Answer:
Explanation: Atomic weight is measured in atomic mass units (amu), also called daltons.
Determine the structure for a compound Z with formula C10H803.
i think it's a simple covalent structure
Check the box under each molecule in the table below that is an isomer of this molecule:
The branched alkanes in boxes two and three all have molecular formula C6H14 and are isomers of the compound shown.
Isomers are compounds that has the same molecular formula but different structural formulas. Hence, isomers of compounds can be represented by the same molecular formula since they contain the same number of each atom.
The molecule shown has molecular formula C6H14. The branched alkanes in boxes two and three all have molecular formula C6H14 and are isomers of the compound shown.
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In what way is the Moon like the Earth?
The Moon has volcanoes.
The Moon has an atmosphere.
The Moon has oceans and seas.
The Moon is a solid, rocky body.
PLS ANSWER RIGHT ILL GIVE BRAINLIST :)
Answer:
The Moon has an atmosphere.
Explanation:
The Moon has an atmosphere, but it is very tenuous. Gases in the lunar atmosphere are easily lost to space. Because of the Moon's low gravity, light atoms such as helium receive enough energy from solar heating so that they escape in just a few hours.
explain how materials are suited for different uses based on their physical and chemical properties?
In which case would recalibrating a thermometer be an important next step in an experiment dealing with boiling points?
A) The results of several trials are all very close to each other, but they are noticeably different from the accepted value for the boiling point.
B) A small number of trials are conducted, with results quite different from each other, and with an average that is noticeably different from the accepted value.
C) A single trial is conducted, and the result is very close to the accepted value of the boiling point.
D) The results of several trials vary by a large amount, but the average is close to the accepted value for the boiling point.
I believe the answer would be D
if one gram of sulphur dioxide contains x molecules what will be the number of molecules in 1g of methane
The ratio of molecules in sulphur dioxide and methane will be the same as the ratio of their moles. So, first of all we should find out the number of moles of sulphur dioxide in 1 gram of sulphur dioxide in 1 gram of sulphur dioxide, and the number of moles of methane in 1 gram of methane. This can be done as follows :
(i) The molecular formula of sulphur dioxide is [tex]SO_{2}[/tex]
So, [tex]1[/tex] mole of [tex]SO_{2}[/tex] = [tex]Mass[/tex] [tex]of[/tex] [tex]2'O'[/tex]
[tex]=32+2*16[/tex]
[tex]= 64[/tex] grams
Now, [tex]64g[/tex] of sulphur dioxide [tex]= 1[/tex] mole
So, [tex]1g[/tex] of sulphur dioxide = [tex]\frac{1}{64}[/tex] mole
Thus, we have [tex]\frac{1}{64}[/tex] mole of sulphur dioxide and it contains molecules in it. Now, since equal moles of all the substance contain equal number of molecules, therefore, [tex]\frac{1}{64}[/tex] mole of methane will also contain x molecules of methane.
(ii) Molecular formula of methan is [tex]CH_{4}[/tex]
So, 1 mole of [tex]CH_{4}[/tex] = Mass of C + Mass of 4 H
[tex]=12+4*12[/tex]
Now, 16g of methane = 1 mole
So, 1 g of mathane = [tex]\frac{1}{16}[/tex] mole
We know that:
[tex]\frac{1}{64}[/tex] mole of methane contains = x molecules
So, [tex]\frac{1}{16}[/tex] mole of contains will contain =[tex]\frac{x*64}{16}[/tex] molecules
=[tex]4x[/tex] molecules
what happens when you combine hydroxide, chlorine, and 2 drops of h2o
Answer:
Chlorine will react in water to form hypochlorous acid, which can then dissociate into hydrogen and hypochlorite ions, according to Eqn (1). This reaction is very important, as the disinfecting power of HOCl, hypochlorous acid, is about 40–80 times that of OCl−, hypochlorite.Explanation:
CARRY ON LEARNINGAND REMEMBER DO ALWAYS READ AND WRITE
A bottle rocket takes off with a speed of 13 m/s and is angled 55 degrees above the horizon. What is the Y component of the velocity ?
Answer:
10.53m/s
Explanation:
Initial velocity: 13m/s
Angle of projection: 55deg
Y-component of velocity is given as usin⌀
Plugging in, we get
= 13 * sin(55deg)
= 13 * 0.81
= 10.53
⇒ 10.53m/s
I don’t wanna fail if you know the answer pls help me :(
Answer:
liquid and gas........................
what percentage of oxygen is attributed fossil fuel combustion
A.43%
B.77%
C.4%
D.17%
Answer:
C. 4%
Explanation:
The answer is 4%
*WILL GIVE BRAINLIEST* Which of the following best approximates the percentages of sand, clay, and silt in a sandy loam? Use the soil texture table below to answer.
A. Sand 40
Clay 30
Silt 30
B. Sand 60
Clay 10
Silt 30
C. Sand 20
Clay 60
Silt 20
D. Sand 25
Clay 15
Silt 60
According to Dalton's atomic theory, atoms
a: of different elements combine in simple whole-number ratios to form compounds
b: can be divided into protons, neutrons, and electrons
c: of all elements are identical in size and mass
d: can be destroyed in chemical reactions
According to Dalton's atomic theory, atoms of different elements combine in simple whole-number ratios to form compounds.
DALTON'S ATOMIC THEORY:As the name implies, Dalton's atomic theory is a theory proposed by an English scientist named John Dalton in the 1900's.
The Dalton's atomic theory is composed of five main parts, which are as follows:
All matter is comprised of tiny, definite particles called atoms.Atoms are indivisible and cannot be destroyed.All atoms of a particular element are identical in size and weight.Atoms of different elements contain different mass.Atoms of different elements combine in fixed whole-number ratios when forming compounds.Therefore, in accordance to Dalton's atomic theory, atoms of different elements combine in simple whole-number ratios to form compounds.
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Will the following replacement reaction occur? MgCl2 + I2 → ?
Yes, it will because chlorine is less reactive than iodine.
No, it will not because iodine is less reactive than chlorine.
No, it will not because iodine and chlorine will not bond.
Yes, it will because the iodine will replace the magnesium.
The replacement reaction will not occur because iodine is less reactive than chlorine.
REPLACEMENT REACTION:A replacement reaction is a type of reaction in which one element is replaced by another in a compound.
The principle behind one element replacing the other is based on the reactivity of an element. A more reactive element will displace a less reactive one.
According to this question, the following displacement reaction is given: MgCl2 + I2 → ?
This reaction will not occur because chlorine is more reactive/electronegative than iodine, hence, iodine cannot displace it.
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Nitrogen H2 has :
a)Double bonds
b)Bounded by 6 electrons
c) The bond is ionic
d) Can forms der Waals bonds
e) B& d
Answer:
the bond is ionic
Explanation:
pls ansswerrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Answer: Its C, c is a solid state
the answer :
Hi there !
The answer is "C"
; due to the intermolecular forces of attraction
find the molar mass of 8.54 x 10²⁴ g A₂O₃
Very Very sorry
It takes 120 mL of 0.15 M of carbonic acid (H2CO3) to neutralize 300 mL of sodium hydroxide (NaOH) for the following balanced chemical reaction:
2NaOH + H2CO3 → N2CO3 + 2NaOH
The concentration of the sodium hydroxide _____.
0.03 M
0.24 M
0.12 M
0.06 M
The valence electrons of a krypton (Kr) atom in the ground state are located in the
A. first energy level (shell).
B. second energy level (shell).
C. third energy level (shell).
D. fourth energy level (shell).
Answer:
D
Explanation:
The valence electrons are the outer electrons and must be located in the outermost shell. In this case, D.