Answer:
A. 4.0 mol
Explanation:
Divide 16 g by the molar mass of He, which is 4.0 g/mol.
16 g / 4.0 g/mol = 4.0 mol
2. Calculate the concentration (in molarity) of a NaOH solution if 25.0 mL of the solution are needed to neutralize 17.4 mL of a 0.312 M HCl solution.
Answer:
0.217 M NaOH
Explanation:
M1V1 = M2V2
M1 = 0.312 M HCl
V1 = 17.4 mL HCl
M2 = ?
V2 = 25.0 mL NaOH
Solve for M2 --> M2 = M1V1/V2
M2 = (0.312 M)(17.4 mL) / (25.0 mL) = 0.217 M NaOH
what role does the grass play in the food web?
A. Producer B. Primary Consumer C. secondary Consumer D. Decomposer
Answer:
Producer
Explanation:
I took the test :)
if 23.1g of O2 occupies a volume of 5.0L at a particular temperature and pressure, what volume will 2.50g of Oxygen gas occupy under the same conditions?
Answer:
0.54 L
Explanation:
First we convert the given masses of O₂ into moles, using its molar mass:
23.1 g ÷ 32 g/mol = 0.722 mol2.50 g ÷ 32 g/mol = 0.078 molThen we can solve the problem using Avogadro's law, which states:
V₁n₂=V₂n₁Where:
V₁ = 5.0 Ln₂ = 0.078 molV₂ = ?n₁ = 0.722 molWe input the data:
5.0 L * 0.078 mol = V₂ * 0.722 molAnd solve for V₂:
V₂ = 0.54 LPLEASE HURRY! What is the name of this alkane?
A skeletal model has a hexagon ring with points at the top and bottom. C H 3 is bonded to the top point, and a carbon and another C H 3 are bonded to the bottom right point.
1-methyl,3-ethylnonane
1-methyl,5-ethylisohexane
1-ethyl,3-methylcyclohexane
1-ethyl,5-methylcyclohexane
Answer:
C. 1-ethyl, 3-methylcyclohexane
(Photo for proof at the bottom.)
Explanation:
The 1-ethyl is because you start numbering from the longest branch, towards the next closest branch. Prefix "eth-" means two, there are 2 carbons in the longest branch. 3-methyl is because the next branch is at number 3, and prefix "meth-" means 1, there is 1 carbon in that chain. "Cyclo" in cyclohexane means the skeletal model is shaped like a ring, and the "hexane" means there are 6 carbons in the ring. Prefix "hex" means 6.
Here's a photo of the unit review on Edge. Refer to the 2nd attachment for a visualization.
Please click the heart if this helped.
Answer:
C. 1-ethyl,3-methylcyclohexane
Explanation:
A mole equals 6.02 x 10^23 . Answer these questions below.
1. How many ants are in 1.25 moles of ants?
2. How many moles of pencils are in 4.92 * 10^26 pencils?
3. How many molecules are in 0.26 moles of molecules?
4. How many moles of molecules are in 3.46 * 10^19 molecules?
5. 5.3 * 10^20 atoms are equal to how many moles of atoms?
6. 0.11 moles of atoms are equal to how many atoms?
Answer:
1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants
2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils
3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules
4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules
5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms
6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms
I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.
A truck accelerates at a rate of 14 m/s2 . The truck weighs 17000 kg. What is the amount of force
necessary for the truck to accelerate at this rate?
Answer:
238000 N
Explanation:
Use F=ma
Mass= 17000 kg
Accel.= 14 m/s²
What is the volume of .80 g of O2 gas at STP?
Answer:0.56L
Explanation:Molar mass of O2=32
N=0.8/32
N=0.025
V=0.025 x 22.4=0.56L
5 ways light changes objects
Which term describes something that displays all the characteristics of life?
a.homeostasis
b.organism
c.stimulus
d.unicellular
what do you mean by carrier
Answer:
1 : one that carries : bearer, messenger. 2a : an individual or organization engaged in transporting passengers or goods for hire. b : a transportation line carrying mail between post offices.
Question 10 of 23
Which characteristic makes a digital signal more useful than an analog signal
for storing information?
A. A digital signal includes a spectrum of colors.
B. A digital signal is more difficult to copy.
C. A digital signal cannot be heard by humans.
O D. A digital signal moves between a discrete number of values.
Answer: O D. A digital signal moves between a discrete number of values.
Explanation:
The digital signals are considered more reliable over the analog signals as they encode the information in a coded form. The bits or samples of the data are transmitted and converted into digital and numerical value. The stream of encoded data is in the form of continuous data at regular time intervals. It provides information in waveform and the data is in compact form. The data is in the form of binary bits 0 and 1 so greater the number of bits greater will be the greater will be the resolution of the information.
Mixtures that would be considered buffers include which of the following? I. 0.10 M HCl + 0.10 M NaCl II. 0.10 M HF + 0.10 M NaF III. 0.10 M HBr + 0.10 M NaBr
Answer:
II. 0.10 M HF + 0.10 M NaF.
Explanation:
A buffer system may be formed in one of two ways:
A weak acid and its conjugate base.A weak base and its conjugate acid.Which of the following mixtures could be considered a buffer?
I. 0.10 M HCl + 0.10 M NaCl. No, because HCl is a strong acid.
II. 0.10 M HF + 0.10 M NaF. Yes, since HF is a weak acid and F⁻ (coming from NaF) is its conjugate base.
III. 0.10 M HBr + 0.10 M NaBr. No, because HBr is a strong acid.
If the rate of decomposition of ammonia, NH3, at 1150 K is 2.10 x 10-6 mol/L/s, what is the
rate of production of nitrogen and hydrogen? Given 2NH3 3H2 + N2
Answer:
3.15 × 10⁻⁶ mol H₂/L.s
1.05 × 10⁻⁶ mol N₂/L.s
Explanation:
Step 1: Write the balanced equation
2 NH₃ ⇒ 3 H₂ + N₂
Step 2: Calculate the rate of production of H₂
The molar ratio of NH₃ to H₂ is 2:3. Given the rate of decomposition of NH₃ is 2.10 × 10⁻⁶ mol/L.s, the rate of production of H₂ is:
2.10 × 10⁻⁶ mol NH₃/L.s × 3 mol H₂/2 mol NH₃ = 3.15 × 10⁻⁶ mol H₂/L.s
Step 3: Calculate the rate of production of N₂
The molar ratio of NH₃ to N₂ is 2:1. Given the rate of decomposition of NH₃ is 2.10 × 10⁻⁶ mol/L.s, the rate of production of N₂ is:
2.10 × 10⁻⁶ mol NH₃/L.s × 1 mol N₂/2 mol NH₃ = 1.05 × 10⁻⁶ mol N₂/L.s
Step 1: When we Write the balanced equation
Then 2 NH₃ ⇒ 3 H₂ + N₂Step 2: Calculate the rate of production of H₂
After that, The molar ratio of NH₃ to H₂ is 2:3. Given the rate of decomposition of NH₃ is 2.10 × 10⁻⁶ mol/L.s, the rate of production of H₂ is:Now 2.10 × 10⁻⁶ mol NH₃/L.s × 3 mol H₂/2 mol NH₃ = 3.15 × 10⁻⁶ mol H₂/L.sStep 3: Calculate the rate of production of N₂
After that, The molar ratio of NH₃ to N₂ is 2:1. Given the rate of decomposition of NH₃ is 2.10 × 10⁻⁶ mol/L.s, the rate of production of N₂ is:Now 2.10 × 10⁻⁶ mol NH₃/L.s × 1 mol N₂/2 mol NH₃ = 1.05 × 10⁻⁶ mol N₂/L.sLearn more about:
https://brainly.com/question/16814930
how many mg are in 125ml of
phosphoric acid?
Answer:
125000mg
Explanation:
1ml = 1000mg
125(1000) = 125000mg
What is the change in enthalpy when 180 g of water vapor condenses at 100°C? (AH, = 40.67 kJ/mol)
a. 565 kJ
b. -565 kJ c.
-407 kJ d.
407 kJ
Answer:
[tex]Q=-407kJ[/tex]
Explanation:
Hello there!
In this case, considering that the heat has two forms, sensible (variable temperature) and latent (constant temperature), we can notice that phase changes account for latent heat as the temperature remains the same. In such a way, given the enthalpy of vaporization of water, 40.67 kJ/mol, the enthalpy of condensation (reverse process) is the negative value, -40.67 kJ/mol; therefore, the associated latent heat would be:
[tex]Q=180g*\frac{1mol}{18.02g} *-40.67\frac{kJ}{mol} \\\\Q=-407kJ[/tex]
Best regards!
The answer is
C) -407 kJ d
A voltaic cell is constructed in which the anode is a Fe|Fe2 half cell and the cathode is a Cd|Cd2 half cell. The half-cell compartments are connected by a salt bridge. (Use the lowest possible coefficients. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank.) The anode reaction is:
Answer: The Anode reaction is [tex]Fe(s)\rightarrow Fe^{2+}(aq)+2e^-[/tex]
Explanation:
Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.
Oxidation reaction is defined as the reaction in which a substance looses its electrons.Oxidation occurs at anode.
Anode : [tex]Fe(s)\rightarrow Fe^{2+}(aq)+2e^-[/tex]
Reduction reaction is defined as the reaction in which a substance gains electrons. Reduction occurs at cathode.
Cathode : [tex]Cd^{2+}(aq)+2e^-\rightarrow Cd(s)[/tex]
A reaction vessel for synthesizing ammonia by reacting nitrogen and hydrogen is charged with 5.54 kg of H2 and excess N2. A total of 25.6 kg of NH3 are produced. What is the percent yield of the reaction?
Answer:
81.5
Explanation:
smartworks
When 0.20 mol of hydrogen gas and 0.15 mol of iodine gas are heated at 450 °C until equilibrium is established, the equilibrium mixture is found to contain 0.26 mol of hydrogen iodide. The equation for the reaction is as follows
H2((g) + I2(g) ⇋ 2HI(g)
What is the correct expression for the equilibrium constant, Kc?
Answer:
[tex]Kc=\frac{[HI]^2}{[I_2][H_2]}[/tex]
Explanation:
Hello there!
In this case, for these equilibrium problems it is firstly necessary to know the balanced reaction at equilibrium:
H2((g) + I2(g) ⇋ 2HI(g)
Next, by means of the law of mass action, it turns out possible for us to write the required and correct expression for the equilibrium constant by considering the concentrations and the coefficients in the aforementioned reaction:
[tex]Kc=\frac{[HI]^2}{[I_2][H_2]}[/tex]
Best regards!
Which layer of the Earth includes the crust? a atmosphere b hydrosphere c asthenosphere d lithosphere
Answer:
D
Explanation:
Hope that helps :)
A double-replacement reaction takes place when aqueous Na,co, reacts with aqueous Sn(NO3), according to the following equation. Na,co, + Sn(NO,)
You would expect one of the products of this reaction to be
20
Sn2(CO3)2
NaNO,
O Nas
OCNO,
Answer:
[tex]Sn(CO_3)_2[/tex] and [tex]NaNO_3[/tex].
Explanation:
Hello there!
In this case, according to the described chemical reaction between sodium carbonate and tin nitrate, we can write the undergoing chemical reaction:
[tex]2Na_2CO_3+Sn(NO_3)_4\rightarrow Sn(CO_3)_2+4NaNO_3[/tex]
Thus, we notice that the products are strontium carbonate and sodium nitrate, whose formulas are [tex]Sn(CO_3)_2[/tex] and [tex]NaNO_3[/tex] respectively.
Best regards!
Data Collection
Mass of the original sample of mixture (g) 1.558
Mass of recovered naphthalene (g) 0.483
Mass of recovered 3-nitroaniline (g) 0.499
Mass of recovered benzoic acid (g) 0.467
Calculations:
a. % by mass of naphthalene in original sample.
b. % by mass of 3-nitroaniline in original sample.
c. % by mass of benzoic acid in original sample.
d. total percent recovered.
Answer:
For a): The mass percent of naphthalene in the original sample is 31.00 %.
For b): The mass percent of 3-nitroaniline in the original sample is 32.03 %.
For c): The mass percent of benzoic acid in the original sample is 29.97 %.
For d): The total percent recovered is 93.00 %.
Explanation:
Percentage by mass is defined as the ratio of the mass of a substance to the mass of the solution multiplied by 100. The formula used for this is:
[tex]\text{Percent by mass}=\frac{\text{Mass of substance}}{\text{Mass of a solution}} \times 100[/tex] ......(1)
a):
Mass of naphthalene = 0.483 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of naphthalene}=\frac{0.483 g}{1.558}\times 100\\\\\%\text{ mass of naphthalene}=31.00 \%[/tex]
b):
Mass of 3-nitroaniline = 0.499 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of 3-nitroaniline}=\frac{0.499 g}{1.558}\times 100\\\\\%\text{ mass of 3-nitroaniline}=32.03 \%[/tex]
c):
Mass of benzoic acid = 0.467 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of benzoic acid}=\frac{0.467 g}{1.558}\times 100\\\\\%\text{ mass of benozic acid}=29.97 \%[/tex]
d):
Total mass recovered = [0.483 + 0.499 + 0.467] = 1.449 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\text{Total percent recovered}=\frac{1.449 g}{1.558}\times 100\\\\\text{Total percent recovered}=93.00\%[/tex]
Question List
Question 4 of 8
Total Points: 0 out of 80
Calculate the volume that will be occupied by
240 mL of hydrogen, measured at 360 mm Hg, when
the pressure is changed to 1080 mm Hg.
Answer:
80 mL
Explanation:
Step 1: Given data
Initial pressure of hydrogen (P₁): 360 mmHgInitial volume of hydrogen (V₁): 240 mLFinal pressure of hydrogen (P₂): 1080 mmHgFinal volume of hydrogen (V₂): ?Step 2: Calculate the final volume of hydrogen
If we assume ideal behavior and constant temperature, we can calculate the final volume occupied by hydrogen using Boyle's law.
P₁ × V₁ = P₂ × V₂
V₂ = P₁ × V₁/P₂
V₂ = 360 mmHg × 240 mL/1080 mmHg = 80 mL
what is an example of an electrolyte solution?
Answer:
nacl with water
they are capable of conducting electricity
Lab: Measuring pH Table or
Lab Report please ( just link it ) please
Answer:
sorry my phone died lol but here are the answers
<3
It took 14.50 mL of 0.455M NaOH to fully neutralize 12.0mL of HCl. What is the concentration of the HCl?
HCl + NaOH \rightarrow→ NaCl + H2O
Answer:
0.550 M HCl
Explanation:
M1V1 = M2V2
M1 = 0.455 M NaOH
V1 = 14.50 mL NaOH
M2 = ?
V2 = 12.0 mL HCl
Solve for M2 --> M2 = M1V1/V2
M2 = (0.455 M)(14.50 mL) / (12.0 mL) = 0.550 M HCl
Answer:
The appropriate answer is "0.549 M".
Explanation:
The given values are:
N₁ = 14.50 mL
V₁ = 0.455 M
N₂ = 12 mL
Let
V₂ = C = ?
As we know,
⇒ [tex]N_1\times V_1=N_2\times V_2[/tex]
On substituting the values, we get
⇒ [tex]14.50\times 0.455 = 12\times C[/tex]
⇒ [tex]6.5975=12\times C[/tex]
⇒ [tex]C=\frac{6.5975}{12}[/tex]
⇒ [tex]=0.549 \ M[/tex]
True or false. Law of action/reaction: for every action there is an equal and the same reaction. Pls don’t give me a link and tell me the answe
Select the valid ways to make an ammonia/ammonium buffer for use in the laboratory. Mix equal volumes of 1 M NH3 and 0.01 M NH 4. Mix some volume of 1 M NH3 with half as much 1 M HCl. Mix equal volumes of 1 M NH3 and 1 M NH 4. Mix equal volumes of 1 M NH3 and 1 M HCl.
Answer:
The answer is "Option b and Option c".
Explanation:
This buffer is a buffer of ammonia and ammonium ion. Thus it requires the solution [tex]NH_3 \ \ and \ \ NH_4^{+}[/tex].
In point 1:
The solution containing [tex]NH_3 \ \ and \ \ NH_4^{+}[/tex] at 1M concentration would be given by mixing the two solutions. Thus, this buffer is a legitimate route.
In point 2:
It gives the ions you want but they are not the same.
In point 3:
[tex]1 M[/tex] [tex]NH_3[/tex] and [tex]1 M[/tex][tex]HCl[/tex] volume would not produce the same [tex]NH_3 \ \ and \ \ NH_4^{+}[/tex] concentrations. Therefore, this buffer isn't a valid route.
In point 4:
Some [tex]1 M[/tex] [tex]NH_3[/tex] volume and half [tex]HCl[/tex] . This offers the same rate as half.
Identify the most and the least basic compound in each of the following sets. Leave the remaining answer in each set blank. a) Sodium acetate: _______ Ammonia: _______ Sodium ethoxide: _______ b) Sodium acetate: _______ Sodium chloroacetate: _______ Sodium fluoroacetate: _______ c) Sodium acetate: _______ Sodium methoxide: _______ Sodium phenoxide:
Answer:
The correct answer is -
a) Sodium acetate: least Ammonia: _______ Sodium ethoxide: most
b) Sodium acetate: most Sodium chloroacetate: _______ Sodium fluoroacetate: least
c) Sodium acetate: least Sodium methoxide: most Sodium phenoxide:
Explanation:
A) In this case the basicity can be found by the stability of the base, Sodium acetate is the most stable base due to resonance stabilization of acetate anion. Sodium acetate is the least basic as the lone pair of electrons involved in the resonance here. An ethoxide ion has more electrons to donate an electron pair easily.
Thus, the correct answer is - Sodium acetate is the least basic while sodium ethoxide is the most basic.
B) Fluroacetate gives a very strong acid and the acetate gives the least strong acid among all three as described in case of a), thus, the most basic is acetate and the least is fluoroacetate.
]C) comparing the acidity of the acids formed by the addition of a proton to the anions is an easy and correct way to find the basicity of compounds.
Acetate ion adds a proton ⇒ acetic acid
methoxide adds a proton ⇒ methanol
phenoxide ion adds proton ⇒ phenol
As it is known that the stronger the acid, the weaker is the conjugate base formed by the loss of the proton.
acetic acid is the strongest acid because it can easily give up its proton to form acetate. Methanol is the weakest among all three and hence methoxide anion is the strongest base.
Thus, the correct answer is - sodium acetate is the least basic while sodium methoxide is the most basic.
Arrange the following substance into acid,base and neutral. sodium chloride, tomato juice, vinegar,sea water,bicorbonate of sodium
Answer:
sodium chloride: neutral.
tomato juice: acid.
vinegar: acid.
sea water: base.
bicarbonate of sodium: base.
Explanation:
Hello there!
In this case, in agreement to the definition of the pH, as the measure of the acidity and basicity of a substance; it is important to recall that pH's below 7 stand for acidic substances and pH's above 7 stand for basic substances, whereas a pH of 7 defines a neutral one. In such a way, given the pH's of the given substances, 7, 4.05 to 4.65, around 2.5, about 8.1 and about 8.3 respectively for sodium chloride, tomato juice, vinegar, sea water, bicarbonate of sodium, it is possible to assert:
sodium chloride: neutral.
tomato juice: acid.
vinegar: acid.
sea water: base.
bicarbonate of sodium: base.
Best regards!
Suppose you have a 1:1:1 by weight mixture of three solid compounds, salicylic acid 4-nitroaniline naphthalene. You dissolve 1 gram of this mixture in diethyl ether, and place a tiny drop of the ether solution on a TLC plate. After developing the TLC plate, you see three spots. Which compound would would you expect to have the largest Rf value
Answer:
The correct answer is - 4-nitroaniline.
Explanation:
It is given that all three solid compounds salicylic acid + 4-nitroaniline + naphthalene are equal in the ratio in the mixture and then 1 gram of this mixture is dissolved in the diethyl ether and run a drop of the solution on TLC plate. This plate shows three spots.
The salicylic acid and naphthalene would stay dissolved in the diethyl ether solution due to the 4-nitroaniline could be extracted by adding aqueous acid and involve in the aqueous layer and thus spot of 4-nitroaniline would be with largest Rf value.