Answer:
We need 540 mmoles of stock solution and complete to 270 mL of volume.
Explanation:
In order to determine the volume or concentration at diluted solution we apply this formula:
Dil volume . Dil concentration = Conc volume . Conc concentration
Stock solution is always, the concentrated.
Let's replace with data given:
Dil. volume . 2 M = 120 mL . 4.5 M
Diluted volume = (120 mL . 4.5M) / 2M
Diluted volume = 270 mL
This problem can be also solved by rule of three:
1 mL of stock solution contains 4.5 mmoles
120 mL of stock solution contain (120 mL . 4.5 mmoles) / 1mL = 540 mmoles
This mmoles of stock solution are also contained at the diluted
If 2 mmoles are contained in 1mL of diluted solution
540 mmoles must be contained in (540 mmol . 1 mL) / 2 mmol = 270 mL
We need 540 mmoles of stock solution and complete to 270 mL of volume.
What is the volume of 0.150 M sodium hydroxide, required to react completely with 250.0 mL of 0.545 M acetic acid, CH3COOH solution?
Answer:
68.81ml
Explanation:
Using the formula:
CaVa = CbVb
Where;
Ca = concentration of acid (M)
Cb = concentration of base (M)
Va = volume of acid (ml)
Vb = volume of base (ml)
Based on the information given in this question;
Ca = 0.545M
Cb = 0.150M
Va = 250ml
Vb = ?
Using CaVa = CbVb
0.545/250 = 0.150/Vb
Cross multiply
250 × 0.150 = 0.545Vb
37.5 = 0.545Vb
Vb = 37.5/0.545
Vb = 68.81ml
Your simulation involved 100 atoms and eight half-life cycles. For half-life cycles 9 and later, how many radioactive nuclei would you expect to be present?
Answer:
you would expect 0 radioactive nuclei to be present
Explanation:
got it right on the assignment
How many atoms of hydrogen are involved in this reaction?
CH4 + 202 → CO2 + 2H2O
Suppose you will determine the composition of the unknown substance that was collected at the scene of the crime. You are encouraged to work on this case. You can perform a series of tests on the unknown substance and compare results of the same tests performed on known samples. Follow these steps:
List physical properties you can use as a simple method of identifying substances.
Describe how you can use density to help identify unknown substances.
Explain how forensic chemist can help you identify unknown substances.
How important is comparing tests results of know substances in a lab setting?
Answer:
b erergart
Explanation:
Na2 So4
identify the nature of this reaction
Na2SO4 is not an reaction it is a compound named Sodium Sulfate having molar mass 142 g/mol
Dilute hydrochloric acid is gradually added to a solution that is buffered at pH 4.76. How will the pH of the solution be affected?
A. The pH will gradually approach 4.76.
B. The pH will initially remain close to 4.76, then increase quickly when the buffering capacity is exceeded
C. The PH will initially remain close to 4.76 then decrease quickly when the buffer capacity is exceeded
D. The pH will remain close to 4.76 indefinitely
the answer is C.
The PH will initially remain close to 4.76 then decrease quickly when the buffer capacity is exceeded
The acidity or alkalinity of a solution depends upon its hydronium ion concentration and hydroxide ion concentration. The pH will initially remain close to 4.76 then decrease quickly when the buffer capacity is exceeded when dil. HCl is added. The correct option is C.
What is pH?The pH of a solution is defined as the negative logarithm to the base 10 of the value of the hydronium ion concentration in moles per litre. For an acidic solution the pH of the solution is less than 7 and for basic solution the pH is greater than 7.
The pH scale is introduced by the Sorensen is more convenient in expressing the hydronium ion concentration of a solution. The PH will initially remain close to 4.76 then it is suddenly decreases if the buffer capacity is exceeded.
The equation used to calculate the pH is:
pH = -log [H₃O⁺]
Thus the correct option is C.
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1) Calculate the temperature change for mercury if 160 g of the metal absorbs 1500 J of heat energy. Mercury's specific heat is 0.14 J/g°C.
2) How much heat is given out when 85 g of lead cools from 200.0°C? The specific heat of lead is 0.11 J/g°C
3) What is the final temperature of a substance if 1404 J of energy is added to 38 g of it at 26°C? The specific heat is 0.24 J/g°C
Answer:
1. 66.96°C
2. -1776.5J
3. 179.9°C
Explanation:
Using the formula;
Q = m × c × ∆T
Where;
Q = amount of heat (J)
m = mass (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
QUESTION 1:
∆T = ?
m = 160g
c = 0.14 J/g°C
Q = 1500 J
1500 = 160 × 0.14 × ∆T
1500 = 22.4∆T
∆T = 1500/22.4
∆T = 66.96°C
QUESTION 2:
Q = ?
m = 85g
c = 0.11 J/g°C
∆T = 10°C - 200°C = -190°C
Q = 85 × 0.11 × -190
Q = -1776.5J
QUESTION 3:
Q = 1404 J
m = 38g
c = 0.24 J/g°C
Final temperature = ?
Initial temperature = 26°C
1404 = 38 × 0.24 × (T2 - 26)
1404 = 9.12 (T2 - 26)
1404 = 9.12T2 - 237.12
9.12T2 = 1404 + 237.12
9.12T2 = 1641.12
T2 = 1641.12 ÷ 9.12
T2 = 179.9°C
Which of the following shows the 3 main jobs of a cell?
a
make energy, recycle all cells, dispose of cells
b
make proteins, dispose of cells, digest food
c
make energy, make proteins, make more cells
d
digest food, dispose of cells, recycle all cells
5) answer is A
2NaHCO3(s) + 129k) - Na2CO3(s) + H2(g) + CO2(g)
This equation indicates that AH is
and energy must be
to complete the reaction.
A)
positive; added
B)
negative; added
C)
positive; released
D)
negative; released
Answer:
A) positive; added
Explanation:
Based on the reaction:
2NaHCO3(s) + 129kJ → Na2CO3(s) + H2(g) + CO2(g)
2 moles of NaHCO3 requires 129kJ to produce 1 mole of Na2CO3, 1 mole of H2 and 1 mole of CO2.
That means, the energy must be added being, thus, an exothermic reaction. The exothermic reactions have ΔH >0.
Thus, right answer is:
A) positive; added
HELP!! :))
I’ll give Brainliest to whoever balances the equation and says what the theoretical and percent yields are of the equation :)
Select the structure that corresponds to the molecule name:
Answer:
Option B
Explanation:
The name of the molecule is;
1,1,1,3,3,3-Hexachloropropanone
Now, we can see that it contains propanone which is also called acetone. So it will have a double bond with Carbon(C) and Oxygen (O).
Option B has that double bond between C and O that indicates it propanone or acetone.
Thus, it is the correct option.
Answer:
It is a ( on the acellus question )
Explanation:
Most types of commercial flour are sifted
before they are packaged and sold in the
store. What effect do you think this has
on the quality of the flour?
Answer:
It improves the texture of the flour
Explanation:
Flour is supposed to have a very fine texture. Commercial flour is not expected to occur in lumps. Lumps reduce the utility of the flour.
Hence, to improve the texture of the commercial flour, it is thoroughly sifted to ensure that there are no large lumps in the flour.This is so important when producing cake flour where the achievement of fine texture is of utmost priority.
When pH changes from 6 to 3, how many times does acidity increase?
Since a pH of 3 is three numbers higher than a pH of 6, we can find the change in acidity by taking 10 to the third power. The solution with a pH of 3 is 1000 times more acidic than the solution with a pH of 6.
The image below shows the jet stream (darker line) moving across the northern United
States and Canada
Which of the following statements correctly describes how the jet stream effects local
weather?
Answer:
Explanation:
add the statements n will answer w/ 'em thanx
A: Air Pressure south of the jet stream is greater than north of the system
B the jet stream moves storms in to areas with its slow level winds.
C Clear nice weather follow along the the near stream as it winds move eastward
D As the jet stream moves southward, it will bring with it cooler temperatures
ans is d
what does the distance traveled by each component on the paper strip in paper chromatography depend on
Answer:
PLZ FOLLOWING ME.........................
10. Stronger IMFs (intermolecular forces) lead to... ?
1.higher MP and BP
2. unique coloration of compounds
3.lower MP and BP
4. weird names of compounds
Type the correct answer in the box. Express your answer to three significant figures. Iron(II) chloride and sodium carbonate react to make iron(II) carbonate and sodium chloride: FeCl2(aq) + Na2CO3(s) → FeCO3(s) + 2NaCl(aq). Given 1.24 liters of a 2.00 M solution of iron(II) chloride and unlimited sodium carbonate, how many grams of iron(II) carbonate can the reaction produce? The reaction can produce grams of iron(II) carbonate.
Answer:
The reaction can produce 287 grams of iron(II) carbonate
Explanation:
To solve this question we must find the moles of iron(II) chloride that react. Using the chemical equation we can find the moles of iron(II) carbonate and its mass -Molar mass FeCO3: 115.854g/mol-
Moles FeCl2:
1.24L * (2.00mol / L) = 2.48 moles FeCl2
As 1 mol FeCl2 produce 1 mol FeCO3, the moles of FeCO3 = 2.48 moles
Mass FeCO3:
2.48mol * (115.854g / mol) =
The reaction can produce 287 grams of iron(II) carbonateAnswer:
287
Explanation:
22. Oxidation occurs when materials containing _______________________ are exposed to oxygen and water
Answer:
iron
Explanation:
iron reacts with oxygen easily causing rust to form. the haemoglobin in your red blood cells contains haem which is iron and that's how your body transfers oxygen all over
What would be the temperature change if 3.0 g of water absorbed 15 J of heat? Specific Heat capacity of water= 4.18 J/gºC
Question 19 options:
a
None of the above
b
2.4 ºC
c
1.2 ºC
d
15 ºC
را
Which statement describes an intensive property of matter?
O It is the same for every sample of a single substance.
O It depends on how a substance was formed.
O It is the same for every sample of every substance.
O It depends on the amount of substance present.
Answer:
A.It is the same for every sample of a single substance.
Explanation:
A student finds that the water's temperature went from 18oC to 38oC. Calculate how many calories are in the peanut.
Answer:
567 calories.
Explanation:
There 567 calories in 100 grams of peanut. In 100 grams of peanut, 49 gram is the fat, 26 grams of protein, 16 grams of carbohydrates, Sodium is 18 mg, Potassium is 705 mg. Calcium is present in peanut about 9%, Iron is 25% , Vitamin B-6 is 15% and Magnesium is 42% of their total weight. Oil content is high in the Peanut so this is the reason for high calories in peanut. It is a good source of proteins and potassium.
HELP ASAPPPP""""A 0.0200 M NaCl solution was formed when 38.0 grams of NaCl was dissolved in enough water. What was the total volume of the solution formed? (5 points)
32.5 liters
30.3 liters
26.7 liters
22.1 liters
Answer: The volume of the solution formed will be 32.5 L. Explanation: Molarity is defined as the amount of solute present in 1 L of solution. The equation used to determine molarity of the solution follows: We are given: Molarity of the solution = 0.02 mol/L Mass of NaCl = 38 grams Molar mass of NaCl = 58.5 g/mol Putting values in above equation, we get: Hence, the volume of the solution formed will be 32.5 L.
Answer:
32.5
Explanation:
What are the basic forces that drive the water cycle? Explain what they are.
Answer:
kcgiobb jkffiob hffyio hiiddhoo hhioiv
Answer: Have a blessed day
Explanation:
Water Cycle: Component # 1. Evaporation:
Evaporation is the process where a liquid changes from its liquid state to a gaseous state. Liquid water becomes water vapour. Temperature is the primary factor for evaporation.
During the water cycle the water of the oceans and freshwater bodies, such as lakes and rivers, is warmed by the sun and evaporates. During the process of evaporation, impurities in the water are left behind. As a result, the water that goes into the atmosphere is cleaner than it was on Earth.
Water Cycle: Component # 2. Condensation:
Condensation is the opposite of evaporation. Condensation is the process where a gas is changed into a liquid. Condensation occurs when the temperature of the vapour decreases.
The water droplets formed from condensation are very small and they remain suspended in the atmosphere. There millions of droplets of suspended water form clouds in the sky or fog at ground level. Water condenses into droplets only when there are small dusts particles present around.
Water Cycle: Component # 3. Precipitation:
When the temperature and atmospheric pressure are right, the small droplets of water in clouds form larger droplets or raindrops and it is called precipitation. The raindrops fall to earth.
As a result of evaporation, condensation and precipitation, water travels from the surface of the Earth goes into the atmosphere, and returns to Earth again.
Water Cycle: Component # 4. Surface Runoff:
Much of the water that returns to Earth as precipitation runs off the surface of the land and flows down-hill into streams, rivers, ponds and lakes. Small streams flow into the ocean. Surface runoff is an important part of the water cycle because, through surface runoff, much of the water returns again to the oceans, where a great deal of evaporation occurs.
Water Cycle: Component # 5. Infiltration:
ADVERTISEMENTS:
Infiltration is an important process where rain water soaks into the ground, through the soil and underlying rock layers. Some of this water ultimately returns to the surface at springs or in low spots downhill. Some of the water remains underground and is called groundwater.
As the water infiltrates through the soil and rock layers, many of the impurities in the water are filtered out. This filtering process helps in cleaning of the water.
Water Cycle: Component # 6. Transpiration or Evapotranspiration:
This is performed by plants. As plants absorb water from the soil, the water moves from the roots through the stems to the leaves. Once the water reaches the leaves, some of it evaporates from the leaves, adding to the amount of water vapour in the air. This process of evaporation through plant leaves is called transpiration. In large forests, an enormous amount of water will transpire through leaves.
what's a way of remembering all Diatomic molecules
Explanation:
The Diatomic molecules include, Hydrogen, Oxygen, Fluorine, Bromine, Iodine, Nitrogen, and Chlorine. A way to remember them is HOFBRINCL which has the symbols of all Diatomic molecules.
Someone pls help i am being timed!!!!
Answer:
i think it is a the full moon
how does the behavior of the particles determine the properties of the state of matter?
Answer:
Solid matter is composed of tightly packed particles. A solid will retain its shape; the particles are not free to move around. Liquid matter is made of more loosely packed particles. ... Gaseous matter is composed of particles packed so loosely that it has neither a defined shape nor a defined volume.\
Answer:
if they are more stable and more still they are solid if they are slitly agitated and move around more then it's a liquid but if they are completely moving fast without any hesitation then it's a gas.
24.
What is the molar mass of CO2?
Answer:
The molecular mass of carbon dioxide is 44.01amu
Choose ALL
BIOTIC factors
Lesson 5.01
Question 1 options:
protists
animals
fungi
plants
salinity
Answer:
protists
animals
fungi
plants
Explanation:
i took the test let me know if im wrong tho
The biotic factors from the following options are protist, animals, fungi, and plants. Options A, B, c, and D are correct.
What are biotic factors?Biotic factors are those factors which can grow, and reproduce themselves.
Plants, animals, protists, and fungi are biotic factors that live, eat ad reproduce.
Salinity is the quality of any solution. It is not a biotic factor.
Thus, the correct options are A, B, c, and D.
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Who goes to K12 and if so what grade
Answer:
I do. I am in tenth. What area are you in?
Explanation:
Answer:
8th finna be in 9th wbu
Explanation:
You throw a barbeque for your friends. Before you start the grill, your propane tank has a pressure of 78 psi. When you’re finished grilling, the temperature is 95°F and the propane tank reads 74 psi. Come nighttime the outside temperature drastically decreases to 20°C. What is the pressure of the propane tank at night?
Select one:
a. 16 kPa
b. 485 kPa
c. 107 kPa
d. 2300 kPa
Answer:
b. 485 kPa
Explanation:
Gay-Lussac's law express that the pressure of a gas under constant volume is directly proportional to the absolute temperature. The equation is:
P1T2 = P2T1
P is pressure and T absolute temperature of 1, initial state and 2, final state of the gas
Where P1 = 74psi
T2 = 20°C + 273.15 = 293.15K
P2 = ?
T1 = (95°F -32) * 5/9 + 273.15 = 308.15K
Replacing:
74psi*293.15K = P2*308.15K
70.4psi
In kPa:
70.4psi * (6.895kPa / 1psi) =
b. 485 kPa