Answer:
Lower the pH slightly
Explanation:
The mixture of HF, hydrofluoric acid and KF, potassium fluoride produce a buffer that is defined for the equilibrium:
HF(aq) → H⁺(aq) + F⁻(aq)
The buffer can maintain the pH of a solution despite the addition of strong bases or acids.
The reaction of HF with Ca(OH)2 is:
2HF + Ca(OH)2 → 2H2O + CaF2
That means the calcium hydroxide is decreasing the concentration of HF. Based on the equilibrium, the H+ and F- ions will decrease in order to produce more HF. As H+ is decreasing due the equilibrium and not for the addition of a strong base, the pH is decreasing slightly.
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.
What is one movement that liquid water CANNOT do while on or at the Earth's surface? (GIVE RIGHT ANSWER OR I DELETE 100 POINTS)
Answer:
One movement that i can't do is float in mid air
Explanation:
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!
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.
Which of the following would result in being able to dissolve a greater amount of gas in a solution?
Answer:
Lower the temperature of the solution
If the fan and power source are not connected to anything else, the amount of electrical energy is the same as the amount of mechanical energy. What is this rule known as?
1. transference of energy
2. conversion of energy
3. adaptation of energy
4. conservation of energy
Answer:
not B
Explanation:
my friend got it wrong
1. Which individuals are most likely to die before reproducing, those with adaptive traits or
nonadaptive traits? Why? (Hint: You may use the newt population as an example in your
explanation.)
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.......................
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:
A 0.150-kg sample of a metal alloy is heated at 540 Celsius an then plunged into a 0.400-kg of water at 10.0 Celsius, which is contained in a 0.200-kg aluminum calorimeter cup. The final temperature of the system is 30.5 Celsius. What is the specific heat of the metal alloy in J/Kg.Celsius
Answer:
[tex]C_{alloy}=0.497\frac{J}{g\°C}[/tex]
Explanation:
Hello there!
In this case, according to this calorimetry problem on equilibrium temperature, it is possible for us to infer that the heat released by the metal allow is absorbed by the water for us to write:
[tex]Q_{allow}=-(Q_{water}+Q_{Al})[/tex]
Thus, by writing the aforementioned in terms of mass, specific heat and temperature, we have:
[tex]m_{alloy}C_{alloy}(T_{eq}-T_{alloy})=-(m_{water}C_{water}(T_{eq}-T_{water})+m_{Al}C_{Al}(T_{eq}-T_{Al})[/tex]
Then, we solve for specific heat of the metallic alloy to obtain:
[tex]C_{alloy}=\frac{-(m_{water}C_{water}(T_{eq}-T_{water})+m_{Al}C_{Al}(T_{eq}-T_{Al})}{m_{alloy}(T_{eq}-T_{alloy})}[/tex]
Thereby, we plug in the given data to obtain:
[tex]C_{alloy}=\frac{-(400g*4.184\frac{J}{g\°C} (30.5\°C-10.0\°C)+200g*0.900\frac{J}{g\°C}(30.5\°C-10.0\°C)}{150g(30.5\°C-540\°C)} \\\\C_{alloy}=0.497\frac{J}{g\°C}[/tex]
Regards!
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.
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:
10 ml of a 0.25M solution is diluted to make exactly 250 ml of solution. What's the concentration of the diluted solution?
Answer:
0.01 M
Explanation:
As this problem deals with a dilution process, we can solve it by using the following formula:
C₁V₁=C₂V₂Where subscript 1 stands for the initial concentration and volume, while 2 stands for the final conditions.
That means that in this case:
C₁ = 0.25 MV₁ = 10 mLC₂ = ?V₂ = 250 mLWe input the given data:
0.25 M * 10 mL = C₂ * 250 mLC₂ = 0.01 MWhy 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.
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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what is the most metallic item on the pterotic table
Answer:
francium or cesium
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
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
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
What would the products be for the reaction between Na3PO4 + MgSO4?
MgSO4 + Na3PO4 = Na2SO4 + Mg3(PO4)2
Answer: The products of Na3PO4 + MgSO4 are Na2SO4 + Mg3(PO4)2
Explanation:
Hl Weakly dissociates in water according to the chemical equation below. H20+ Hl <-> H3O^+ + l- What is a conjugate acid-base pair in this reaction?
Answer:
https://www.clutchprep.com/chemistry/practice-problems/70217/hi-aq-h2o-l-h3o-aq-i-aq-identify-each-as-either-a-bronsted-lowry-acid-bronsted-l
Explanation:
https://www.clutchprep.com/chemistry/practice-problems/70217/hi-aq-h2o-l-h3o-aq-i-aq-identify-each-as-either-a-bronsted-lowry-acid-bronsted-l
How are solutions and compounds similar?
Answer:
hope you liked it!!!!!!
A compound is a pure substance that is composed of elements chemically bonded in definite proportions. A compound can be broken down into simpler substances only by chemical reactions, such as electrolysis.
A solution is a homogeneous mixture, meaning that it is the same throughout. A solution is composed of one or more solutes dissolved in a solvent. The proportions of the solute(s) can vary, as the components of a solution are not chemically bonded. The components of a mixture can be separated by physical means, such as filtration and distillation
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)
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.
The enthalpy of formation of water is -285.8 kJ/mol. What can be inferred from this statement? O The enthalpy of the products is equal to the enthalpy of the reactants. O Heat is absorbed during the process. O Heat is released during the process. The enthalpy of the products is more than the enthalpy of the reactants.
Answer:
the answer is c
Explanation:
i did the test
The enthalpy of the formation of water is -285.8 kJ/mol. The information that can be made by the statement is heat is released during the process. The correct option is C.
What is enthalpy?Enthalpy is the volume times the pressure times the internal energy of the system. It is an entity of thermodynamics. It is the measurement of the energy in a thermodynamic system. The enthalpy totals the internal energy plus pressure and volume.
The statement that is given here is given that enthalpy is -285.8 kJ/mol. The value is negative, so the energy is released here. When energy is gained the energy will be positive and when the energy is released it is negative.
Thus, the correct option is C, heat is released during the process regarding the given statement of enthalpy.
To learn more about enthalpy, refer to the link:
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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
12. An electrolysis reaction is
A. hydrophobic.
B. spontaneous.
C. exothermic.
D. non-spontaneous.
Answer: D.) non-spontaneous.
Explanation:
By what factor does [OH- ] change when the pH increases by 1.7?
Use the equations below to calculate the enthalpy of formation for propane gas, C3H8, from its elements, hydrogen gas and solid carbon. Please hurry!!
Answer: I got -4542.9kg/mol
Explanation:
Using the enthalpy relation, the enthalpy of formation of propane gas in the given equation is 4542.9 kJ/mol
[tex] △H_{f} = Product [/tex]Using the enthalpy value of [tex] CO_{2} [/tex] and[tex] H_{2}0[/tex] given :
Product = [tex] 3CO_{2} + 4H_{2}0[/tex] Product = 3(-393.5) + 4(-285.8) = - 2323.70Reactant = [tex] C_{3}H_{8} + 5H_{2}0[/tex] Water, H20 has △H = 0Reactant = [tex] C_{3}H_{8} + 0[/tex]
Enthalpy of formation = product - Reactant
2219.2 = -2323.70 - (propane + 0)
2219.2 = - 2323.70 - propane
Propane = - 2323.70 - 2219.2
[tex] C_{3}H_{8} = - 4542.9 [/tex]
Therefore, the entalphy of formation of propane gas is - 4542.9 kJ/mol.
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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.