Answer:
nitrogen in atmospheres of a sample is 0.679
True or false? To prepare 20.0 mL of 2.00 M solution of hydrochloric acid from a 10.0 M stock solution, you should take 4.00 mL of the stock solution and add 20.0 mL of water.
False. To prepare 20.0 mL of 2.00 M solution of hydrochloric acid from 10.0 M stock solution, 4.0 mL of the stock solution and 16.0 mL of water would be needed.
Recall the law of diffusion that:
C1V1 = C2V2, where C1 = initial concentration, V1 = initial volume, C2 = final concentration, and V2 = final volume.
In this case, if C1 =10.0 M, V1 = ?, C2 = 2.00 M and V2 = 20.0 mL
V1 = 2 x 20/10
= 4.0 mL
Hence, 4.0 mL of the stock solution would be taken. Since the final volume is 20.0 mL, only 16.0 mL of water would need to be added and not 20.0 mL.
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Ohio Achievement Test Coach Science, Grade 5
10. Bob first blows whistle hard. Then he blows the same whistle gently. What
changed when Bob blew the whistle the second time?
POSTTEST
A pitch
B. volume
C. pitch and volume
D. frequency
Will award brainliest! Between which two ionization energies would you expect to see the biggest jump for calcium? A. 11-12
B. 12-13
C. 13-14
D. 14-15
answer:lettter B that is answer
What happens during high tide?
a.The tidal range is at its minimum in a location.
b.The tidal range is at its maximum in a location.
c.The water level in the ocean rises to above average water level.
D.The water level in the ocean drops to below average water level.
Answer: c
Explanation:
Plants and animals need to protect themselves to survive. Select the statement that best describes the adaptions of animals and plants.
Ammonia (NH3) dissolved in water is heated in a beaker. If initially there had been 60 grams dissolved in 100 grams of water, what would happen if the temperature reached 90℃ and why? A. The solution would become supersaturated and the ammonia would all remain dissolved . B. The solution would become saturated but the amount of ammonia dissolved would remain the same . C. about 50 more grams of ammonia would be able to dissolve as the solution has become unsaturated . D. about 50 grams of ammonia would come out of solution as the temperature caused the solubility to decrease .
Answer:
C. About 50 more grams ammonia would be able to dissolve as the solution has become unsaturated
Explanation:
From the question, we have;
The mass of ammonia dissolved in water = 60 grams
The mass of the water solvent which dissolves the ammonia = 100 g
The temperature to which the ammonia water solution is raised = 90°C
Therefore, given that the solubility of a solute in a solvent increases with temperature, when the temperature is raised, we have, that the solution will more unsaturated and will be able to dissolve more ammonia, therefore, option 'C' is the most correct option that corresponds with the relationship of temperature and solubility
help please see attached file
Answer:
balanced equation of glucose
6CO2 + 6H2O----------C6H12O6 + 6O2
in the presence of sun light.
This is agree or disagree I need help ASAP!!
Answer:
disagree
sometimes they attract
Explanation:
Answer:
Explanation:
2. Agree
3. Agree
4. Agree
5. agree
6. disagree
If im wrong its because im tired lol
The equation A+ BX à AX + B is the general equation for a
Answer: d
Explanation:
took the test
What happens to the average speed of gas molecules as the temperature increases? Why?
Answer:
Average speed increases because average kinetic energy increases.
Explanation:
Temperature is the measure of the average kinetic energy of a system. As temperature increases, so will kinetic energy. As kinetic energy increases, speed increases.
HELP!!!!
please omg
Answer:
I believe it's A. to reduce air bubbles. Tbh, it's been a while
What is the mass in grams of 4.8 moles of Calcium Hydroxide?
Answer:
355.2 grams
Explanation:
m = M×n= (40 + 2(16+1))×4.8= 355.2 (g)
Compared with halogens, the alkali metals in the same period has
electronegativity
the same
O larger
O smaller
Can someone balance this equation
CH₄ + 2O₂ = CO₂ + 2H₂O
how many periods are there in the modern periodic table of elements?
Answer:
There are seven periods in the modern periodic table.
Answer:
Seven periods
Explanation:
There are seven periods in the periodic table, with each one beginning at the far left. A new period begins when a new principal energy level begins filling with electrons. Period 1 has only two elements (hydrogen and helium), while periods 2 and 3 have 8 elements.
Because the triple beam balance is zeroed before it is put into use, it measures
A.
volume
B.
weight
C.
the effects of gravity
D.
mass
Different substances have....
A.the same properties
B. different properties
C.similar properties
D.all properties
Answer:
Different properties
Explanation:
They are different.
3. The mass percent of nitrogen in NH4Cl is *
O 16.7% nitrogen
0 25.0% nitrogen
0 26.2% nitrogen
O none of these
Answer:
None of these
Explanation:
The mass percent is 35.4% (3 s.f.)
14/4+35.5 = 14/39.5 x 100 = 35.4 (3 s.f.)
Can you build a fire on the moon? Why or why not?
Answer:
No.
Explanation:
We can't build a fire on the moon, because moon's atmosphere lacks oxygen.
[tex] \huge \pink{answer}[/tex]
No lightning of a fire on the surface of the moon is impossible..
[tex] \huge \green {reasons - }[/tex]
surface of the moon lacks oxygen which is important for the formation of fire.Surface of the moon doesn't have wind which disables the fire to burn rapidly.if life had existed during thie won the fossils probably would not have survived because
Answer:
because life would have use fossil for their benefits.
Determine the representative particles of
0.075 mol Ti
2.10 mol CO2
Answer:
0.o75 mol Ti = 4.5x10∧22
2.10 mol CO2 = 1.26x10∧24 molecules
hope this helped
Which of these do NOT show malleability a) Iron
b) Sulfur
c) Copper
d) Aluminum
Answer:Sulfur
Hope this helps!
Explanation:
2) Why do some earthquakes cause more damage than others?
Answer:
Earthquakes are more intense the faster the planet's crust slams together, which explains why the shaking causes so much damage in some of the most populated areas around mountain chains. ... One reason for this connection is that when two plates come together quickly, the area over which an earthquake occurs is larger.Explanation:
Which statement is correct?
A. Physical changes produce new substances; chemical changes do not.
B. Chemical changes produce new substances; physical changes do not.
C. Both physical changes and chemical changes produce new substances.
D. Neither physical changes nor chemical changes produce new substances.
Answer:
B. Chemical changes produce new substances; physical changes do not.
Explanation:
Physical changes only alter appearances, while chemical changes are interactions that create new chemical formulas.
How many grams are in 26 moles of
magnesium hydroxide?
1,516.31168 grams of Magnesium Hydroxide
You are melting a chocolate and accidentally have the stove up to high. the chocolate starts to burn on the bottom of your pot. Physical or Chemical Change?
Answer:
it is a chemical change because it can't be change back to it normal position when it gets burnt
i have a quiz yall help
How many moles are in a 18 L tank of nitrogen gas at STP?
Answer:
12
Explanation:
i feel like its 12 because moles are medium sized but are they adult moles or baby moles or growing moles
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 0.803moles of nitrogen gas are there in a 18 L tank of nitrogen gas at STP.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
Mathematically,
number of moles of any ideal gas =given volume ÷Volume occupied by one mole of a ideal gas at STP
Volume occupied by one mole of a ideal gas at STP=22.4L
given volume of nitrogen gas= 18 L
substituting all the given values in the above equation we get,
number of moles of nitrogen gas =18 L ÷22.4L
number of moles of nitrogen gas =0.803moles
Therefore, 0.803moles of nitrogen gas are there in a 18 L tank of nitrogen gas at STP.
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A solution has a pOH of 5.
What is the pH?
Classify the solution as acid, base, or neutral.
Answer:
pH is the number given to a substance of how powerful it is before 7 or beyond 7.
the solution is an acid.
Explanation:
Pls mark BRAINLIEST
Answer:
August 15, 1971
The nine sheikhdoms still had not agreed on terms of union by 1971, however, prompting Bahrain to declare itself fully independent on August 15, 197
1.A solution has a pH of 5, calculate the pOH, [H+], and [OH-]. Classify the solution as an acid, base, or neutral solution.
it's an acid
Explanation:
I hope that this helps
What is the percent composition (by mass) of MgBr2?
Answer:
13.2% Mg, 86.8% Br
Explanation:
Mg has a molar mass of 24.31g/mol.
Bromine has a molar mass of 79.90 g/mol.
There is one mole of Mg and two moles of Br in the compound:
79.90x2 + 24.31 = 184.11
So the total molar mass of MgBr2 is 184.11.
A percent tells us a part of a whole, so we will divide each part of the mass into the whole mass.
24.31g Mg / 184.11g MgBr2 = .132
159.8g Br / 184.11g MgBr2 = .868
Multiply these decimals by 100 to make them into a percent.
.132 x 100 = 13.2% Mg
.868 x 100 = 86.8% Br
As the randomness of a system increases, the entropy of the system:
A) decreases
B) increases
C) remains the same
Answer:
it most likely increases