Answer:
Empirical formula is CH
Explanation:
A hydrocarbon, CₐHₓ reacts with oxygen in the combustion reaction as follows:
CₐHₓ + O₂ → a CO₂ + x/2 H₂O
That means we can find the moles of C and H from the moles of CO2 and H2O. As empirical formula is defined as the simplest whole-number ratio of atoms in a molecule, we can determine it as follows:
Moles CO2 = Moles C -Molar mass: 44.01g/mol:
0.4225g * (1mol / 44.01g) = 0.0096 moles C
Moles H2O -Molar mass: 18.01g/mol:
0.0865g H2O * (1mol / 18.01g) = 0.0048moles H2O * (2mol H / 1mol H2O) =
0.0096 moles H
The ratio of atoms of C:H is:
0.0096moles C / 0.0096moles H = 1
That means empirical formula is CH
A student reads a barometer in the laboratory and finds the prevailing atmospheric pressure to be 736 mmHg. Express this pressure in torr and in atmospheres.
Answer:
736 mmHg = 0.97 atm (Approx.)
736 mmHg = 736 Torr
Explanation:
Given barometer in the laboratory atmospheric pressure data:
Atmospheric pressure in mmHg = 736 mmHg
Find:
Change given data into Torr
Change given data in atm (atmospheric pressure)
Computation:
We know that;
1 atm = 760 mmHg
So,
736 mmHg = 736 / 760
736 mmHg = 0.97 atm (Approx.)
We know that;
760 mmHg = 760 Torr
So,
736 mmHg = 736 Torr
For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH. If the solubility does change, pick the pH at which you'd expect the highest solubility. You'll find Ksp data in the ALEKS Data tab. compound Does solubility change with pH
Answer: Hello attached below is the complete question and using data from ALEKS data tab
answer:
PbCl₂ : Yes , PH = 3
CaC0₃ : Yes, PH = 3
AgCn : Yes , PH = 3 .
Explanation:
For PbCl₂
PbCl₂ solubility will change ( decrease ) with increase in PH, and the PH at which PbCl₂ will be most soluble is at PH = 3
For CaC0₃
Addition of -ions which increases the PH level will cause a decrease in the solubility of CaC0₃ hence the PH at which it will be most soluble in an aqueous solution is PH = 3
For AgCn
Increase in the PH level there would be a decrease in the solubility of AgCn hence the PH at which AgCn is most soluble ( highest solubility ) = 3
The ability of a solute to be able to dissolve is called solubility. Yes, at pH 3, the solubility of lead chloride, calcium carbonate, and silver cyanide.
What is solubility?The ability of the solute to get dissolved in a solvent to form a saturated solution is called solubility.
For lead chloride, the solubility will decrease as the pH will increase and is most soluble at a pH of 3.
For calcium carbonate, the addition of ions increases the pH will result in a decreased solubility, and will be most soluble at pH 3.
For silver cyanide increased pH decreases the solubility and is most soluble at a pH of three.
Therefore, solubility decrease with an increase in pH due to the concentration factor.
Learn more about solubility here:
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Which two statements describe organ systems working together to bring
oxygen to cells?
O A. Blood vessels carry oxygen from the lungs to the heart.
B. Cells use oxygen to turn nutrients from food into energy.
C. The lungs allow oxygen from the air to enter the blood.
D. The brain monitors the level of oxygen in arteries.
Answer: A and C are the right answer.
Explanation:
When 100 identical steel balls are placed on a
triple beam balance, their mass is determined to
be 1,450 grams. The mass of a single steel ball
would be closest to
Explanation:
thank you for the points
How can heat energy transform from mechanical energy?
A)Burning
B)Friction
C)Light
D)Flames
Answer:
A
Explanation:
brainliest pls
12. An electrolysis reaction is
A. hydrophobic.
B. spontaneous.
C. exothermic.
D. non-spontaneous.
Answer: D.) non-spontaneous.
Explanation:
The molar mass of water is 18.02 g/mol. A mass of 160.0 grams of water is equivalent to how many moles?
please show work!
Answer:
8.879 moles.
Explanation:
From the question given above, the following data were obtained:
Molar mass of water = 18.02 g/mol
Mass of water = 160.0 g
Mole of water =?
Mole is defined by the following equation:
Mole = mass / molar mass
With the above formula, we can obtain the number of mole present in 160 g of water. This can be obtained as follow:
Molar mass of water = 18.02 g/mol
Mass of water = 160.0 g
Mole of water =?
Mole = mass / molar mass
Mole of water = 160 / 18.02
Mole of water = 8.879 moles.
Therefore, 160 g of water contains 8.879 moles.
A sample of gas at 90 degrees Celsius occupies 15.5 L. This gas is heated to occupy a new volume of 20.3L. What is the new temperature of the gas?
Answer:
202 °C
Explanation:
From the question given above, the following data were obtained:
Initial temperature (T₁) = 90 °C
Initial volume (V₁) = 15.5 L
Final volume (V₂) = 20.3 L
Final temperature (T₂) =?
Next, we shall convert 90 °C to Kelvin temperature. This is illustrated below:
T(K) = T(°C) + 273
Initial temperature (T₁) = 90 °C
Initial temperature (T₁) = 90 °C + 273
Initial temperature (T₁) = 363 K
Next, we shall determine the final temperature.
Initial temperature (T₁) = 363 K
Initial volume (V₁) = 15.5 L
Final volume (V₂) = 20.3 L
Final temperature (T₂) =?
V₁ / T₁ = V₂ / T₂
15.5 / 363 = 20.3 / T₂
Cross multiply
15.5 × T₂ = 363 × 20.3
15.5 × T₂ = 7368.9
Divide both side by 15.5
T₂ = 7368.9 / 15.5
T₂ ≈ 475 K
Finally, we shall convert 475 K to celsius temperature. This is illustrated below:
T(°C) = T(K) – 273
T₂ = 475 – 273
T₂ = 202 °C
Thus, the new temperature of the gas is 202 °C
Why would a doctor most likely restrict a patient’s contact with other people while the patient receives internal radiation?
A. The patient’s stress and anxiety would be eliminated.
B. High levels of radiation can diffuse through the patient’s skin.
C. Social contact would increase the effect of the radiation treatment.
D. Radioactive material can leave the patient’s body through saliva, sweat, and urine.
Answer:
D.......................
Charge q is 1 unit of distance away from the source charge S. Charge p is two times further away. The force exerted
between S and q is the force exerted between S and p.
O 1/2
O 2 times
O 1/4
O 4 times
Answer:1/4
Explanation:
A certain mass of water was heated with 41,840 Joules, raising its temperature from 22.0°C to 28.5 °C. Find the
mass of the water.
Answer:
1.5 × 10³ g
Explanation:
Step 1: Given and required data
Transferred heat (Q): 41,840 JInitial temperature: 22.0 °CFinal temperature: 28.5 °CSpecific heat capacity of water (c): 4.184 J/g.°CStep 2: Calculate the temperature change
ΔT = 28.5°C - 22.0 °C = 6.5 °C
Step 3: Calculate the mass (m) of water
We will use the following expression.
Q = c × m × ΔT
m = Q / c × ΔT
m = 41,840 J / (4.184 J/g.°C) × 6.5 °C = 1.5 × 10³ g
By what factor does [OH- ] change when the pH increases by 1.7?
1. How does a virus differ from a common cell?
A. It has no nucleus, cell wall, or organelles.
B. It has two nuclei and no cell wall or organelles.
C. A virus has no cell well, no nucleus, and only organelles for
movement.
D. A virus differs from a cell only in shape.
Cell membranes are selectively permeable. This means that A. only water can move freely across the cell membrane. B. any substance can move across the cell membrane, but chemical energy will always be required. C. some substances can move freely across the cell membrane, while others must be transported. D. no substances can move freely across the cell membrane.
Answer:
C. some substances can move freely across the cell membrane, while others must be transported.
Explanation:
differences between diamond and graphite
Answer:
dimond is stronger
Explanation:
Answer:
Graphite and Diamond are different because they have different structures. ... However each carbon atom in Diamond has 4 covalent bonds with other Carbons, making it extremely strong and hard. On the other hand, each carbon in graphite is bonded to three carbons, and therefore graphite is formed in layer
Also:
Each carbon atom in a diamond is linked to four other carbon atoms. Each carbon atom in graphite is linked to three other carbon atoms. Diamond is poor conductor of electricity due to the absence of free electrons. Graphite is good conductor of electricity due to the presence of free electrons in its structure.
Explanation:
Hope this helps
Fu/kushima Daiichi nuclear disaster (Research)
1. When and where did this accident happen?
2. Describe the incident and cause.
3. Who was responsible?
4. How many people were injured or died? (short term and long term)
5. How could the accident have been prevented?
6. What chemicals were involved?
7. What are the chemicals physical and chemical properties? (refer to their safety data sheets)
8. What are the chemicals uses, what products are they used in?
9. What health problems did the accident cause?
10. Relate details from the accident to chemistry topics we have covered so far
11. Compare and contrast the safety protocols used at the time of the accident to current safety practices for the same chemical.
Answer:
I don't know
Explanation:
give me you research
Help plz:)))I’ll mark u Brainliest
Answer:
[tex]\Delta _{fus}H=205J/g=13.03kJ/mol[/tex]
Explanation:
Hello there!
In this case, since the heat of fusion is a property that allows us to calculate the heat involved during the change from solid to liquid (fusion) and is calculated as shown below:
[tex]Q=m*\Delta _{fus}H[/tex]
In such a way, given the heat involved during this process and the mass of copper, we calculate the heat of fusion as shown below:
[tex]\Delta _{fus}H=\frac{Q}{m}=\frac{41000J}{200.g}\\\\\Delta _{fus}H=205J/g[/tex]
Or in kJ/mol:
[tex]\Delta _{fus}H=205\frac{J}{gCu}*\frac{63.546 gCu}{1molCu}\\\\ \Delta _{fus}H=13026.93J/mol=13.03kJ/mol[/tex]
Regards!
Which one is a transferable type of energy?
A. Potential
B. Heat
C. Internal
D. Stored energy
E. Kinetic
Answer:
E. Kinetic
Explanation:
Kinetic Energy. Energy is transferred from one object to another when a reaction takes place. Energy comes in many forms and can be transferred from one object to another as heat, light, or motion, to name a few. For the blue ball to move to the position of the green ball, energy must be given to the blue ball.
Brainlyest please
Why is a wire used to connect the electrodes in an electrochemical cell?
O A. To provide the metal that is the oxidizing agent
B. To prevent the flow of protons from electrodes
C. So ions can flow from one electrode to another
D. So electrons can flow from one electrode to another
Answer:
D. So electrons can flow from one electrode to another
Explanation:
An electrochemical cell is any cell in which electricity is produced by reason of a chemical change.
An electrochemical cell consists of two electrodes, these two electrodes are connected using a wire.
Usually, electrons flow from one electrode to another via this wire thereby enabling the electrochemical processes of oxidation and reduction in the cell to proceed effectively.
Information normally shown as a continuous wave is analog or digital. Examples include music cds and smartphones is it analog or digital. Takes up a lot of space and degrades over time is it analog or digital. Examples include dimmer light switches and cameras that use film is it analog or digital. Purer data is more accurate and has more details is it analog or digital. Please help
Answer:
Music CDs and smartphones are digital.
Explanation:
Music CDs and smartphones are digital. Analogue takes up a lot of space and degrades with the [passage of time while on the other hand, digital takes less space and degrades in large piece of time. Dimmer light switches and cameras that use film is it analog not digital. The major difference between both signals is that the analog signals have continuous electronic signals, while digital signals have non-continuous electronic signals.
How much water, in grams, can be made from 1.84 × 1024 hydrogen molecules?
Answer:
55.0g water can be made
Explanation:
To solve this question, we must convert the molecules of H2 to moles using Avogadro's constant. With the moles, and the reaction:
H2 + 1/2O2 → H2O
We can find the moles of H2O = Moles H2 and its mass of using molar mass of water -H2O = 18.01g/mol-
Moles H2 = Moles H2O:
1.84x10²⁴ molecules * (1mol / 6.022x10²³ molecules) = 3.055 moles H2O
Mass:
3.055 moles H2O * (18.01g / mol) = 55.0g water can be made
Which substance is the best oxidizing agent?
A. NaOH
B. H2O
C. Xe
D. HCI
E. O3
Answer:
the answer is A.
Explanation:
Elemental fluorine, for example, is the strongest common oxidizing agent.
Explain what matter is, and all of the states it can have.
Answer:
matter is anything that occupies space
states of matter : solid,liquid, gas,plasma
Answer:
matter can be anything, tables chairs, literally anything. it has volume and takes up space.
Explanation:
Solids, liquids, gases, plasmas, and Bose-Einstein condensates (BEC)
1. What are the five symbiotic relationships?
2. What is mutualism? Explain mutualism with an example and a picture.
3. What is commensalism? Explain with an example and a picture.
4. What is predation? Explain with an example and a picture.
5. What is parasitism? Explain with an example and a picture.
6. What is competition? Explain with an example and a picture.
Write a CER paragraph (5- 8 complete sentences) answering the following prompt:
Why are symbiotic relationships important in an ecosystem?
Answer:
1) There are five main symbiotic relationships: mutualism, commensalism, predation, parasitism, and competition.
2) The term mutualism can be simply defined as a relationship in which both species are mutually benefited. This relationship can either be within the species or between the two different species. ... Here ants are the mutualist and acacia trees is the host. The acacia tree provides home and food for the ants.
3) Commensalism is a type of symbiotic relationship in which one species benefits, while the other species is neither harmed nor helped. The species that gains the benefit is called the commensal. ... An example is a golden jackal (the commensal) following a tiger (the host) to feed on leftovers from its kills.
4) Predation is the interaction between organisms in which one organism known as the predator kills another organism which is known as prey. ... Examples of predation are a lion eating deer or a snake eating rats. This results in the transfer of energy from the prey to the predator.
5) Parasitism is generally defined as a relationship between the two living species in which one organism is benefitted at the expense of the other. The organism that is benefitted is called the parasite, while the one that is harmed is called the host. A few examples of parasites are tapeworms, fleas, and barnacles.
6) Competition is a negative interaction that occurs among organisms whenever two or more organisms require the same limited resource. ... For example, animals require food (such as other organisms) and water, whereas plants require soil nutrients (for example, nitrogen), light, and water.
Symbiotic relationships are important because they are a major driving force of evolution. This networking and cooperation among species allows them to survive better than they would as individuals.
Purification of copper can be achieved by electrorefining copper from an impure copper anode onto a pure copper cathode in an electrolytic cell. How many hours will it take to plate 19.5 kg of copper onto the cathode if the current passed through the cell is held constant at 38.5 A
Answer: It will take 425 hours to plate 19.5 kg of copper onto the cathode if the current passed through the cell is held constant at 38.5 A.
Explanation:
The half-reaction equation is as follows.
[tex]Cu^{2+} + 2e^{-} \rightarrow Cu[/tex]
According to the standard values, 1 mole of an electron carries 96500 C. Therefore, charge carried by 2 moles of electrons is [tex]2 \times 96500 C[/tex].
Also, atomic mass of Cu is 63.5 g. According to the equation 2 moles of electrons are depositing 63.5 g of Cu.
Hence, charge required to deposit 19.5 kg (1 kg = 1000 g) or 19500 g of Cu is calculated as follows.
[tex]19500 g Cu \times \frac{2 \times 96500 C}{63.5 g Cu}\\= 5.92 \times 10^{7} C[/tex]
Formula used to calculate time is as follows.
[tex]Q = I \times t[/tex]
where,
Q = charge
I = current
t = time
Substitute the values into above formula as follows.
[tex]5.92 \times 10^{7} C = 38.5 \times t\\t = \frac{5.92 \times 10^{7} C}{38.5}\\= 1.53 \times 10^{6} sec[/tex]
As 1 hour contains 3600 seconds. So, converting seconds into hours as follows.
[tex]1.53 \times 10^{6} sec = 1.53 \times 10^{6} sec \times \frac{1 hr}{3600 sec}\\= 425 hr[/tex]
Thus, we can conclude that it will take 425 hours to plate 19.5 kg of copper onto the cathode if the current passed through the cell is held constant at 38.5 A.
please help
A container containing 5.00 L of a gas is collected at 100 K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure (as required by Charles' Law)?
Answer:
[tex]T_2=400K[/tex]
Explanation:
Hello there!
In this case, according to the given information for this question, it turns out possible for us to calculate the final temperature, after the expansion process, by using the well-known Charles' gas law:
[tex]\frac{T_2}{V_2}=\frac{T_1}{V_1}[/tex]
Thus, we solve for the final temperature to obtain:
[tex]T_2=\frac{T_1V_2}{V_1}[/tex]
And plug in the given values:
[tex]T_2=\frac{100K*20.0L}{5.00L}\\\\T_2=400K[/tex]
Regards!
200.0g of a 3.0% NaF solution, how much distilled water do we weigh out?
197g of distilled water
194g of distilled water
140g of distilled water
170g of distilled water
Answer:
194g of distilled water.
Explanation:
Hello there!
In this case, according to the given information for this problem, it turns out possible for us to use the given mass of the solution and the percent by mass of NaF to firstly calculate the grams of this solute as shown below:
[tex]\%m=\frac{m_{solute}}{m_{solution}} *100\%\\\\m_{solute}=\frac{\%m*m_{solution}}{100\%} \\\\m_{solute}=\frac{3.0\%*200.0g}{100\%} \\\\m_{solute}=6g[/tex]
And finally, since the mass of solution is calculated by adding mass of solute and mass of solvent we obtain the mass of water (solvent) as follows:
[tex]m_w=200g-6g=194g[/tex]
Therefore, the answer is 194g of distilled water
Regards!
There are four stages to the classical demographic transition model Pre-transitional Europe was characterized by high and
fluctuating mortality and a high birth rate. The transition model began to progress into and through stage 2 in the late 18th and early
19th century. All BUT ONE contributed to the decline in mortality.
S- -1]))
A)
Enacting measures to provide clean water supplies.
B)
Public health advances including quarantine of settlements undergoing
epidemics
The development of vaccines to prevent disease and antibiotics to treat
infection.
D)
Widespread acceptance of germ theory resulting in more hygienic
practices, including hand washing and sterilizing medical equipment and
infants' bottles.
How many sulphur atoms are there in 0.125 moles of sulphur
Explanation:
There are 6.022x1023 molecules in 1 mole of SO3 (Avogadro's number) so in 0.25 moles, there are (0.25)(6.022x1023) molecules in the 0.25 moles of SO3. or 1.506x1023 molecules per 0.25 moles of SO3.
There is one atom of sulfur in each molecule of SO3. So there are 1.506x1023 atoms of sulfur in 0.25 moles of SO3.
According to the concept of Avogadro's number there are 0.7525 ×10²³ atoms of sulfur in 0.125 moles of sulfur.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
In the given example, number of atoms of sulfur are calculated as, Avogadro's number×number of moles, that is,6.022×10²³ ×0.125=0.75275×10²³ atoms
Therefore, there are 0.75275×10²³ atoms in 0.125 moles of sulfur.
Learn more about Avogadro's number,here:
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130 cm of a gas at 20°C exerts a pressure of
750 mm Hg. Calculate its pressure if its volume
is increased to 150 cm3 at 35 °C.
Answer: The pressure is 1137.5 mm Hg its pressure if its volume is increased to 150 [tex]cm^{3}[/tex] at 35 °C
Explanation:
Given: [tex]P_{1}[/tex] = 750 mm Hg, [tex]V_{1} = 130 cm^{3}[/tex], [tex]T_{1} = 20^{o}C[/tex]
[tex]P_{2}[/tex] = ?, [tex]V_{2} = 150 cm^{3}[/tex], [tex]T_{2} = 35^{o}C[/tex]
Formula used to calculate the new pressure is as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{750 mm Hg \times 130 cm^{3}}{20^{o}C} = \frac{P_{2} \times 150 cm^{3}}{35^{o}C}\\P_{2} = 1137.5 mm Hg[/tex]
Thus, we can conclude that the pressure is 1137.5 mm Hg its pressure if its volume is increased to 150 [tex]cm^{3}[/tex] at 35 °C.