Answer:
just awser
eeww
Explanation:
Which
gas is exchanged in the air sac of
longs? -
oxygen and nitrogen
oxygen and carbondioxide
O nitrogen and coarbondioxide
oxygen and hydrogen
O
Other:
Answer:
oxygen and carbon dioxide.
hope this helps you
Which statement describes the atoms in an element
Answer:
Atoms are kind of like building blocks.
Explanation:
Think of atoms as kind of like a mix between paint pigments and legos. The more legos that you have, the bigger the molecule but keep in mind that there are many different kinds of legos that all can come together to build numerous things. I hope that I answered your question and i apoligize if I didn't.
Which laws protect citizens against human trafficking
Answer:
It depends on the country you are coming from. For example, the human trafficking laws in the US are different from UK. If you need an essay on this contact me on (irenedavid at g mail dot com)
Explanation:
Calculate the pressure of 2.50 Liters of a gas at 25.0oC if it has a volume of 4.50 Liters at
STP.
Answer:
P_2 =0.51 atm
Explanation:
Given that:
Volume (V1) = 2.50 L
Temperature (T1) = 298 K
Volume (V2) = 4.50 L
at standard temperature and pressure;
Pressure (P1) = 1 atm
Temperature (T2) = 273 K
Pressure P2 = ??
Using combined gas law:
[tex]\dfrac{P_1V_1}{T_1} = \dfrac{P_2V_2}{T_2} \\ \\ \dfrac{1 *2.5}{298} = \dfrac{P_2*4.5}{273}[/tex]
[tex]0.008389261745 \times 273 = 4.5P_2[/tex]
[tex]P_2 =\dfrac{0.008389261745 \times 273 }{4.5}[/tex]
[tex]P_2 =0.51 \ atm[/tex]
What is the pOH of .12 M HNO3.
Choose the molecule or compound that exhibits dipole-dipole forces as its strongest intermolecular force.
BCl3CBr4SO2H2H2O
Answer:
SO2
Explanation:
Dipole-Dipole exist between parmanent dipoles in a molecule. THis means that molecule must have a parmanent dipole moment in it.
Example - HCl
Hydrogen bonding is an attraction between lone pair of an electronegative element and H atom of same or different molecule. H must be covalantly attached to either F, N or O.
Example - H2O
Among the molecules given in the list only SO2 and H2O exihibits parmanent moment. As BCl3 , CBr4 and H2 are symmetric compounds.
Since, SO2 cannot exihibit H- bonding only dipole-dipole forces as its strongest intermolecular force.
What physical property describes the ability of a substance to dissolve?
Answer:
solubility
Explanation:
Can someone give me an example of balancing equations with a solution that is simple?
Explanation:
[tex]H _{2}O _{2(aq)} →H _{2}O _{(l)} + O _{2}(g) \\ solution : 2 \: and\: 2[/tex]
Somebody please answer
60 L of a 180 mol MgCl2 solution is created. What is the molarity of MgCl2 are in this solution?
Explanation:
Molarity = (# of moles)/(# of liters)
= 180 mol MgCl2/60 L
= 3.0M MgCl2
One of the governing laws of the universe is the thermodynamic law of entropy. Which choice best describes entropy?
A. Particles and energy in a system become more and more disordered.
B. Energy is consumed in a chemical reaction.
C. Heat is evenly distributed throughout the universe.
D. More bonds are broken in a chemical reaction than bonds are formed.
A.
Particles and energy in a system become more and more disordered.
A or B or C or D plzz answer fasttt
Answer:
B
Explanation:
Hope this helps! sorry if incorrect
What is the pH of a 0.025 M HCl solution?
12.4
1.6
2.5
05
Answer: pH is 1.6
Explanation: Explanation: HCl is strong acid and it protolyzes totally:
HCl + H2O ⇒ H3O+ + Cl-
Concentrations are same: [H3O+] = c(HCl)
pH = - log[H3O+] = - log(0.025) = 1.60
For the following reaction conditions select the correct statement regarding the reaction below.
OH Cl OTs OTs N TsCl W X Y Z N
a. W is the correct product.
b. X is the correct product.
c. Y is the correct product.
d. Z is the correct product since pyridine acts as a nucleophile.
e. Both X and Y are both formed in this reaction as a racemic mixture
Answer:
B
Explanation:
The appropriate diagram of the question is shown in the first image attached below.
From the diagram, we see the reaction of Cyclopentanol taking place under Tscl pyridine. We are to show the reaction mechanism and determine from the options, which appropriate product fits in.
So, from the reaction, the hydroxyl substituent reacts with Tscl where cl is being lost. This process is followed by an attack of N substituent on the pyridine with the Hydrogen atom and cleaves off for the structure to form a stable structure. The stereochemistry of the compound remains unchanged and it maintains its stick formula.
Thus, X is the appropriate and the correct product.
How much ammonia would it take to neutralize 5ml of apple cider and 5ml of white vinegar if the ammonia had a molarity of 0.25?
Answer:
[tex]m_{NH_3}=0.0213gNH_3[/tex]
Explanation:
Hello there!
In this case, since it is known that the reaction between ammonia and acetic acid is:
[tex]CH_3COOH+NH_3\rightarrow CH_3COONH_4[/tex]
It is possible for us to realize that the mole ratio of acetic acid (vinegar) to ammonia is 1:1, that is why we can relate the concentrations as follows:
[tex]M_{acid}V_{acid}=M_{base}V_{base}\\\\[/tex]
In such a way, by knowing that the volume of these two are the same, we infer that their concentrations is also de same; and therefore, the mass of ammonia is calculated as:
[tex]m_{NH_3}=0.005L*0.25\frac{molNH_3}{L}*\frac{17.04gNH_3}{1molNH_3}\\\\m_{NH_3}=0.0213gNH_3[/tex]
Regards!
A or B or C or D, plz answer fassttt
Answer:
A.
Explanation:
They'd probably want to know the conditions that usually produce fog
What're the differences between oxidation and reduction
Answer:
Oxidation:Oxidation is the loss of electron or Hydrogen atoms or gain of Oxygen atomsRemoval or loss of electronsA ⟶ A⁺ + e⁻
Removal of HydrogenAH + B ⟶ A + BH
Addition of OxygenA + BO ⟶ AO + B
All the above reactions release energy Reduction:Reduction is the gain of electron or Hydrogen atoms or loss of Oxygen atomsAddition or gain of electronsA + e⁻ ⟶ A⁻
Addition of HydrogenA + BH ⟶ AH + B
Removal of OxygenAO + B ⟶ A + BO
All the above reactions stores energy-TheUnknownScientist
A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures 39.0cm wide and 46.8cm high. The maximum safe pressure inside the vessel has been measured to be 5.30MPa. For a certain reaction the vessel may contain up to 7.20kg of sulfur hexafluoride gas. Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius. Round your answer to 3 significant digits.
Answer:
Maximum safe operating temperature = 450 °C
Explanation:
First, the volume of the cylindrical vessel is determined using the formula:
v = πr²h
Radius, r, of stainless steel vessel = width or diameter / 2
r = 39.0 cm / 2 = 19.5 cm
height of vessel = 46.8 cm
volume of cylinder = 22/7 × 19.5² × 46.8 = 55929.343 cm³ = 0.05593 m³
Using the ideal gas equation to calculate the maximum safe temperature
PV = nRT
pressure, P = 5.30 MPa = 5.30 × 10⁶ Pa
R = 8.314 J/mol.K
n = mass of gas/ molar mass of gas
molar mass of SF₆ = 146 g/mol
mass of Sf₆ = 7.20 kg = 7200 g
n = 7200/146 = 49.315 moles
T = PV/nR
T = (5.30 × 10⁶ × 0.05593) / (49.315 × 8.314)
T = 722.98 K
T in °C = 714.98 - 273.15 = 449.83 °C
Therefore, maximum safe operating temperature = 450 °C
Suppose you have a solution that might contain any or all of the following cations: Cu 2, Ag , Ba 2, and Mn2 . The addition of HBr causes a precipitate to form. After the precipitate is filtered off, H2SO4 is added to the supernate, and another precipitate forms. This precipitate is filtered off, and a solution of NaOH is added to the supernatant liquid until it is strongly alkaline. No precipitate is formed. Which ions are present in each of the precipitates
Answer:
Ag⁺, Ba²⁺,
Explanation:
We can solve this question using the solubility rules:
When an Halide as Br- is added to a solution, the ions that can be precipitate are Ag⁺, Hg₂²⁺ and Pb²⁺.
That means the first ion present is Ag⁺
When sulfates, SO₄²⁻ are added, the ions that precipitates are: Ag⁺, Ca²⁺, Sr²⁺, Ba²⁺, Hg₂²⁺ and Pb²⁺
The second ion present is Ba²⁺
Hydroxides of Cu²⁺ and Mn²⁺ are insolubles but as no precipitate are formed when the solution is strongly alkaline those ions are not present.
What is the freezing point (in °C) of a 0.743 m
aqueous solution of KCI?
Enter your rounded answer with
3 decimal places.
K; for water = 1.86 °C/m
Answer: The freezing point (in °C) of a 0.743 m aqueous solution of KCI is [tex]2.763^{o}C[/tex].
Explanation:
Given: Molality = 0.743 m
[tex]K_{f}[/tex] for water = [tex]1.86^{o}C/m[/tex]
The equation for dissociation of KCl when dissolved in water is as follows.
[tex]KCl \rightarrow K^{+} + Cl^{-}[/tex]
As it is giving 2 ions. Therefore, Van't Hoff factor for it is equal to 2.
Formula used to calculate the freezing point is as follows.
[tex]\Delta T_{f} = i \times K_{f} \times m[/tex]
where,
i = Van't Hoff factor
[tex]K_{f}[/tex] = molal depression constant
m = molality
Substitute the values into above formula as follows.
[tex]\Delta T_{f} = i \times K_{f} \times m\\= 2 \times 1.86^{o}C/m \times 0.743 m\\= 2.763^{o}C[/tex]
Thus, we can conclude that the freezing point (in °C) of a 0.743 m aqueous solution of KCI is [tex]2.763^{o}C[/tex].
During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.
What is the amount of the leftover reactant?
0.74 grams of methane
0.89 grams of methane
1.22 grams of oxygen
1.45 grams of oxygen
Answer:d
Explanation:
_____ the irregular break of a mineral.
a. Habit
b. arrangement
c. cleavage
d. Fracture.
Answer:
D Fracture
Explanation:
jus took the test
What is the volume of 1.00 kg of mercury?
Answer:0.074 L
Explanation:
Why is it dangerous to stand under tall trees and building during thunder?
2. All of the following statements are true regarding wood versus metal except: a) Wood has better electrical insulation which decreases with moisture content b) Wood structures dampen vibrations much better than metal, due to internal friction within the materials c) Under sustained loads wood stops to deform d) Wood has much better R value than metals
Answer:
All of the following statements are true regarding wood versus metal except:
c) Under sustained loads wood stops to deform
Explanation:
Wood is known to deform under stress. It undergoes warping, thereby, losing its original straight shape when its moisture unevenly dries up. Even concrete deforms under long-time loads. Similarly, wood, under sustained loads, experiences faster deformation than it ordinarily warps. To prevent further wood deformation, it must be treated, and its moisture dried up evenly.
g Which of the following is TRUE for a system that is in dynamic equilibrium? Which of the following is TRUE for a system that is in dynamic equilibrium? The concentration of products is equal to the concentration of the reactants. The forward reaction goes to 100% completion. Both the forward and reverse reactions come to a halt. The reaction rate of the forward reaction approaches zero. none of the above
Answer:
none of the above
Explanation:
A system is said to have attained dynamic equilibrium when the forward and reverse reactions proceed at the same rate. That is;
Rate of forward reaction = Rate of reverse reaction
The implication of this is that the concentrations of reactants and products remain constant when dynamic equilibrium is attained in a system. This does not mean that the reactant and product concentrations become equal; it rather means that their concentrations do not significantly change once dynamic equilibrium has been attained.
Students are asked to design an experiment with cookies to demonstrate their understanding of the scientific method. One group has decided to determine the amount of time it will take for a cookie to "dissolve" in a glass of milk.
Which variable would most likely NOT affect the time it takes for the cookie to dissolve?
a) the size of the cup of milk
b) the type of cookie
c) the number of students in the group
d) the temperature of the milk
e) the type of milk
I'm gonna guess E on this one, but I think you should choose either E or A
Which statement below can NOT
be used when describing volume?
A. Volume is the amount of space that an object
occupies.
B. The volume of an object is the same as the
weight of that object.
C. Volume can be measured in cubic
centimeters.
D. Volume is calculated using a formula: V = 1x w
xh.
Answer:
the answer is B:
Explanation:
I hope it help.
A mixture of fuel and is injected into a cylinder fitted with a piston. The initial volume is 0.37 L. After the mixture is ignited, gaseous products are formed and 1885 J of energy is released by the reaction. 311 J of the released energy is lost as heat to the surroundings. To what volume would the gases expand against a constant pressure of 1.036 atm, if the remainig energy is converted to work to push the
Answer:
The gases will expand to a volume of 2.37 L
Explanation:
Gases are able to do work when they expand or compress against an external constant pressure.
This work done by gases when they expand or compress against a constant external pressure is known as pressure-volume work or PV work.
The formula for calculating the work done by gases when they compress or expand against a constant pressure is given as W = PΔV
Where ΔV is change in volume given as V2 - V1
Where V2 is final volume, V1 is initial volume
By convention, W can either be negative or positive. When work is done by the system (ΔV > 0), W is negative and when work is done on the system (ΔV < 0), W is positive.
In the gas mixture above, W = PΔV
Remaining energy, W = (1885 - 311) J = 1574 J
P = 1.036 atm = 1.036 × 760 mmHg = 787.36 mmHg
ΔV = V2 - V1
ΔV = V2 - 0.37
1574 = 1.036 (V2 - 0.37)
V2 - 0.37 = 1574/787.36
V2 - 0.37 = 1.999 L
V2 = 1.999 + 0.37
V2 = 2.369 L
Therefore, the gases will expand to a volume of 2.37 L
9. Assuming all other conditions are constant, what is the new pressure of a gas if the original pressure is 50 kPa and the Kelvin temperature is doubled?
a.100kpa
b.25kpa
or D.200kpa
Answer:
Option a (100 kPa) is the appropriate option.
Explanation:
The given value is:
Original pressure,
P₁ = 50 kPa
Let the new pressure be "x".
Now,
⇒ [tex]\frac{P1}{T_1} =\frac{P_2}{T_2}[/tex]
On substituting the values, we get
⇒ [tex]\frac{50}{T_1} =\frac{x}{2T_1}[/tex]
On applying cross-multiplication, we get
⇒ [tex]x = 50\times 2[/tex]
⇒ [tex]=100 \ kPa[/tex]
Thus the answer above is the right one.
The rate of reaction was measured during a chemical reaction. After the first 3 seconds, the rate of reaction was 1.8 x10−6 M/s. Which of the following would you expect after another 3 seconds?
The question is incomplete, the complete question is;
The rate of reaction was measured during a chemical reaction. After the first 3 seconds, the rate of reaction was 1.8 x10−6 M/s. Which of the following would you expect after another 3 seconds? a
The rate would be higher, and the concentration of reactants would be lower.
b
The rate would be higher, and the concentration of reactants would be higher.
c
The rate would be lower, and the concentration of reactants would be lower.
d
The rate would be lower, and the concentration of reactants would be higher.
Answer:
The rate would be lower, and the concentration of reactants would be lower.
Explanation:
The rate of reaction refers to how quickly or slowly the reactants disappear or the products appear in a given reaction. The rate of reaction depends on the concentration of the reactants. Thus, as concentration decreases with time, the rate of reaction decreases accordingly.
Therefore, reaction rates tend to decrease with time since the concentration of the reactants decrease with time as the reactants are being converted into products. Thus after three seconds, the rate would be lower, and the concentration of reactants would be lower. Hence the answer above.
Answer:
The rate would be lower, and the concentration of reactants would be higher.
Explanation:
I took the test and i think i got it right