Answer:
b
Explanation:
How do astronomers know about the future collision of Andromeda and the Milky Way?
A) All galaxies will collide at some point
B) The two galaxies have collided previously
C) Astronomers have observed their movements over time
D) The Milky Way has changed course to head toward Andromeda
Answer:
Astronomers have observed their movements over time
Explanation:
Just took the test!!!
The future collision of Andromeda and milky way are known by astronomers because ; ( C ) Astronomers have observed their movements over time
Andromeda also known as messier 31 is a spiral galaxy that appears as a milky blur when viewed from the earth and it is believed to be slightly over 2.5 million years old.
Astronomers predict that based on its movement and the movement of the Milky way there is most likely going to be a collision in future between the Andromeda and milky way.
Hence we can conclude that The future collision of Andromeda and milky way are known by astronomers because Astronomers have observed their movements over time
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Given:
CH4 + 2O2 → CO2 + 2H2O, ΔH = -890 kJ/mol
How much energy is released when 59.7 grams of methane (CH4) reacts with oxygen?
The combustion of 59.7 grams of methane releases ____ kilojoules of energy
Answer:
The combustion of 59.7 grams of methane releases 3320.81 kilojoules of energy
Explanation:
Given;
CH₄ + 2O₂ → CO₂ + 2H₂O, ΔH = -890 kJ/mol
From the combustion reaction above, it can be observed that;
1 mole of methane (CH₄) released 890 kilojoules of energy.
Now, we convert 59.7 grams of methane to moles
CH₄ = 12 + (1x4) = 16 g/mol
59.7 g of CH₄ [tex]= \frac{59.7}{16} = 3.73125 \ moles[/tex]
1 mole of methane (CH₄) released 890 kilojoules of energy
3.73125 moles of methane (CH₄) will release ?
= 3.73125 moles x -890 kJ/mol
= -3320.81 kJ
Therefore, the combustion of 59.7 grams of methane releases 3320.81 kilojoules of energy
Answer:
The combustion will release -3,321 KJ/mol of energy
Explanation:
What are the four main parts of the Sun? *
Answer: The inner layers are core, radiative zone, and convective zone. The putter layers a photosphere, the chromosphere, the transition region and the corona
PLEASE HURRY
Which substance loses electrons in a chemical reaction?
A.the one that is oxidized, which is the oxidizing agent
B.the one that is reduced, which is the reducing agent
C.the one that is oxidized, which is the reducing agent
D.the one that is reduced, which is the oxidizing agent
Answer:
4) the one that is reduced, which is the oxidizing agent
Explanation:
An oxidizing agent is one that causes oxidation by gaining electrons from another atom/molecule.
Answer:
c
Explanation:
Can matter every be destroyed? Why or why not?
Hey
Matter can neither be created nor destroyed.
Explanation:
This is the law of conservation of matter (mass). One can prove this by performing a simple experiment at home.
Have a great day
What is the concentration of a solution in which 10.0 g of AgNO, is dissolved in 450 mL of solution?
M
Answer:
M=0.15
Explanation:
138 g AgNO -> 1 mol AgNO
10 g AgNO -> x
x= (10 g AgNO * 1 mol AgNO)/138 g x=0.07 mol AgNO
450 mL=0.45 L
M= mol solute/L solution
M= 0.07 mol AgNO/0.45L
M=0.15
Please help with my chemistry! PLEASE
Answer:
b.
Explanation:
Americium decays to neptunium 237.
An alpha particle has 2 protons and 2 neutrons, so 4 helium atoms.
241-4=237
In an ecosystem
1. living things interact with each other
2. living things interact with their environment
3. both of the above
both
Explanation:
an ecosystem is the environment they live in which includes other living things
Answer:
3. both of the above
Explanation:
Living things interact with each other. Suppose you have a pond. It is an ecosystem. The fish in the pond interact with each other, and may even interact with other species like frogs or insect by eating them or living peacefully with them. Living things also interact with their environment such as fishes or some organisms might interact with the plants, logs, the available sunlight, all sorts of these factors which make up the environment.
Thus organisms within an ecosystem interact with each other and their environment.
Which characteristic most likely describes the water in Lake Taal?
Select the correct answer.
o The water will appear slightly red.
O The water will have a slippery feel.
The water will taste bitter.
The water will taste sour.
Answer: The water will taste sour.
Explanation:
Answer: D. The water will taste sour (Edmentum)
Explanation:
Wax is a nonpolar substance . In which type of substance is it the most soluble ?
Answer:
nonpolar
Explanation:
Use the phrase "like dissolves like"
- Hope that helps! Please let me know if you need further explanation.
When humans plant more trees, carbon can begin entering the ____
a- hydrosphere
b- geosphere
c- biosphere
Answer:
biosphere
Explanation:
The carbon cycle is the biogeochemical cycle by which carbon is exchanged between the biosphere, geosphere, hydrosphere and atmosphere of the Earth.
The biosphere refers to the regions of the surface and atmosphere of the earth or another planet occupied by living organisms.
Plants are responsible for taking in carbon in nature. When more trees are planted, carbon is absorbed by plants which is a component of the biosphere. Hence planting more trees means increasing the intake of carbon into the biosphere.
water is a highly polar molecule with strong hydrogen bonding. one of the results of this is that water can climb up a narrow tube. the phenomenom is known as:
A. catapult action (aka trebuchet onfire)
B. capillary action
C. carpel tunnel syndrom
D. capitalization
Answer:
Option B, Capillary action
Explanation:
Water molecules attach with the molecules of the surface of the container in which they are kept. This is because of the cohesive force within the molecules of water and adhesive force between the molecules of water and other substances.
The water rises up in a capillary tube because of water molecules adhere at the edges thereby creating a meniscus in the upside turned direction. The surface is kept intact by the surface tension
Now capillary action specifically occurs when adhesion to the surface of the container is higher than the cohesion between the water molecules.
Hence, option B is correct
How many moles are there in 135g of aluminum ?
Answer:
The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Aluminium, or 26.981538 grams.
If O2(g) reacts with H2(g) to produce H2O, what is the volume of H2O obtained from 1 L of O2?
Hint: Write a balanced equation first!
Answer:
2L
Explanation:
We'll begin by writing the balanced equation for the reaction this is illustrated below:
2H2 + O2 —> 2H2O
1 mole of a gas occupy 22.4L.
1 mole of O2 occupy 22.4L.
2 moles of H2O occupy = 2 x 22.4 = 44.8L.
From the balanced equation above,
22.4L of O2 produced 44.8L of H2O.
Therefore, 1L of O2 will produce = 44.8/22.4 = 2L.
Therefore, 1L of O2 will produce 2L of H2O.
Na2O+H2O= 2NaOH how many grams of Na2O are required to produce 1.06*10^2 grams of NaOH
Answer:
77.5 grams of Na2O
Explanation:
Convert grams to mols.
1.06 x 10^2 grams x 1 mol NaOH/39.99
= 2.50 mols NaOH
Find the mole ratio of NaOH and Na2O
1:2
Convert mols NaOH to Na2O mols
2.50 mols NaOH x 1 mol Na2O/2 mols NaOH
= 1.25 mols Na2O
Convert to grams
1.25 mols Na2O x 61.98 grams Na2O/1 mol
= 77.5 grams Na2O required to produce 1.06 x 10^2 grams of NaOH
1. An airplane flew from San Francisco to Washington, D.C.
Approximately halfway through the flight, the plane had traveled 2,000
km in 2.5 hours. What was the speed during this period?
what does Reproducibility mean? Plz help me
Answer:
the ability to be reproduced or copied.
Explanation:
Answer: the ability of an entire experiment or study to be reproduced, either by the researcher or by someone else working independently.
What is the mass of 3.00 moles of carbon
Answer:
36 grams as 1 mole is 12 grams
Answer:
tbh idk cause I will love to answer your question but ehh
CHEM HELP PLS 30 POINTS!!
1. what volume of 0.20 M HCl (aq) is needed to titrate 50 mL of 0.10 M NaOH to the endpoint?
A) 10.0 mL HCl
B) 40.0 mL HCl
C) 25.0 mL HCl
D) 20.0 mL HCl
2. what is the molarity of a NaOH solution if 40 mL of the solution is titrated to the endpoint with 15 mL of 1.50 M H2SO4?
A) 1.13 M
B) 1.47 M
C) 0.56 M
D) 0.75 M
3. suppose that 10.0 mL of HNO3 is neutralized by 71.4 mL of a 4.2 x 10 ^ -3 M solution of KOH in a titration. Calculate the concentration of the HNO3 solution.
A) 1.0 x 10 ^ -2 M
B) 3.0 x 10 ^ -2 M
C) 5.5 x 10 ^ -2 M
D) 1.0 x 10 ^ -14 M
Balanced equation
HCl + NaOH —> NaCl + H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nA) = 1The mole ratio of the base, NaOH (nB) = 1From the question given above, the following data were obtained:
Volume of base, NaOH (Vb) = 50 mLConcentration of base, NaOH (Cb) = 0.1 MConcentration of acid, HCl (Ca) = 0.2Volume of acid, HCl (Va) =?CaVa / CbVb = nA / nB
(0.2 × Va) / (0.1 × 50) = 1
(0.2 × Va / 5 = 1
Cross multiply
0.2 × Va = 5
Divide both side by 0.2
Va = 5 / 0.2
Va = 25 mL (Option C)
2. How to determine the molarity of NaOHBalanced equation
H₂SO₄+ 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nA) = 1The mole ratio of the base, NaOH (nB) = 2From the question given above, the following data were obtained:
Volume of base, NaOH (Vb) = 40 mLConcentration of acid, H₂SO₄ (Ca) = 1.5 MVolume of acid, H₂SO₄ (Va) = 15 mL Concentration of base, NaOH (Cb) =?CaVa / CbVb = nA / nB
(1.5 × 15) / (Cb × 40) = 1 / 2
22.5 / (Cb × 40) = 1 / 2
Cross multiply
Cb × 40 = 22.5 × 2
Divide both side by 40
Cb = (22.5 × 2) / 40
Cb = 1.13 M (Option A)
3. How to determine the molarity of HNO₃Balanced equation
HNO₃ + KOH —> KNO₃ + H₂O
From the balanced equation above,
The mole ratio of the acid, HNO₃ (nA) = 1The mole ratio of the base, KOH (nB) = 1From the question given above, the following data were obtained:
Volume of base, KOH (Vb) = 71.4 mLConcentration of base, KOH (Cb) = 4.2×10¯³ MVolume of acid, HNO₃ (Va) = 10 mL Concentration of acid, HNO₃ (Ca) =?CaVa / CbVb = nA / nB
(Ca × 10) / (4.2×10¯³ × 71.4) = 1
(Ca × 10) / 0.29988 = 1
Cross multiply
Ca × 10 = 0.29988
Divide both side by 10
Ca = 0.29988 / 10
Ca = 3×10¯² M (Option B)
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Calculate the pressure using the formula P=1.03+ mass on syringe/area of top of syringe
Answer:1.08
Explanation:
Answer:
1.08kg/cm^2
Explanation:
Edge2021
Why might you have difficulty determining the pH of bleach using ph strips?
Answer:
pH test strips will lose colour and their pH sensitivity as strips are made from universal indicator. Universal indicator is composed of phenolphthalein, methyl red, methyl orange and thymol blue.
Explanation:
pH test strips are made from the universal indicator. The universal indicator is composed of phenolphthalein, methyl red, methyl orange, and thymol blue. All of these will react with chlorine in bleach. As a result, they will lose color and pH sensitivity. Due to this, it is difficult to determine the pH of bleach using ph strips.
Which of the following contains polyatomic ion?
Oa
BeHCO
Ob
PCI
Ag!
Mgs
On May 3, Zirbal Corporation purchased 4,500 shares of its own stock for $36,000 cash. On November 4, Zirbal reissued 800 shares of this treasury stock for $7,200. Prepare the May 3 and November 4 journal entries to record Zirbal's purchase and reissuance of treasury stock.
Answer:
Explanation:
Each share costs $36000/4500
= $8
800 shares will cost 800*8
= $6400
Find attached the journal
According to one acid-base theory a molecule acts as an acid when the molecule
ionic compounds conduct electricity in the solid state true or false
In solid form, ionic compounds do not conduct electricity. Ionic compounds will conduct electricity when melted to their liquid state. This is due to the electrons being locked in place when in solid form, but liquid form allows for the electrons to move freely.
If 14 moles of Oxygen burn how many moles of water are created? *
2C2H6
+
702
4CO2 + 6 H2O
A) 12 mol H20
B) 3.5 mol H20
C) 3 mol H20
D) 42 mol H20
Answer:
A) 12 mol H2O.
Explanation:
Hello,
In this case, for the given reaction:
[tex]2C_2H_6+7O_2\rightarrow 4CO_2 + 6 H_2O[/tex]
We notice that oxygen is in a 7:6 molar relationship with water, for that reason, the resulting moles of water turn out:
[tex]n_{H_2O}=14molO_2*\frac{6molH_2O}{7molO_2} \\\\n_{H_2O}=12molH_2O[/tex]
Thus, the answer is A) 12 mol H2O.
Best regards.
5. On what organ does alcohol have the most noticeable effect?
Answer:
the liver
Explanation:
it processes alcohol, work very hard
A sample of diborane gas has a pressure of 345 torr at a temperature of -15c and volume of 3.48L if conditions are changed so that the temperature is 36c and the pressure is 468 torr what will be the volume of the sample
Answer: 3.05L= V2
Explanation:
using
P1V1/T1=P2V2/T2
where p1= 345torr
T1, tempertaure= -15c+ 273=258K
T2, temperature= 36+ 273=309K
p2, Pressure= 468 torr
V2=???
P1V1/T1=P2V2/T2
v2=P1V1T2/T1P2= 345X3.46L X 309/ 258X 468=
V2= 3.05L
(Multiple Choice, 30 pts)
A student thinks that halogens are highly reactive because their electrons are weakly attracted to their nuclei. Which is evidence that disputes this student's idea?
A. Halogens react with alkali metals.
B. Halogens cannot react with noble gases.
C. Halogens tend to attract electrons when bonding.
D. Halogens have a full octet of electrons.
Answer:
c
Explanation:
¨Halogens being non metals have greater electronegativities hence, attract electrons and making the statement disputed. Nobel gases are highly stable; this explains why they are nonreactive. They do not form chemical bonds because they only have a little tendency to either gain or lose an electron; on the other hand, halogens are reactive because they only need one additional electron to complete their octet. ¨
i found that from another users answer for the same question
Answer:
answer c
Explanation:
Which statement describes how a basic coffee cup calorimeter works?
OOO
It measures the mass of a substance given the specific heat and temperature of water in a cup of known size.
It measures the density of a substance given the mass, specific heat, and temperature of water in a cup of known size,
It uses the mass and specific heat of water along with a pressure gauge to measure the gain or loss of energy when a substance is
added.
It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is
added.
Answer:
It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added.
Explanation:
The calorimeter is an instrumental device, which is used to measure the heat of chemical reactions. The heat is measured when the reactants change their state in specified conditions.
The correct answer is:
Option D. It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added.
The coffee cup calorimeter works as:
1. Coffee cup is a type of insulator. The cup of styrofoam with an inserted thermometer can calculate the heat transfer.
2. The thermometer is used to measure the change in the enthalpy of the reaction.
3. The water in the cup absorbs the heat from a reaction, and the cup is adiabatic. Thus, the outer cup is an insulator.
4. The coffee cup measures the specific heat and mass of the water during a chemical change.
Thus, the coffee cup calorimeter uses the heat transfer and mass of the water when a substance is added.
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