Answer:
1. Faster
Explanation:
Which is an example of a current research focus in chemistry?
A. applying gene therapy to treat certain diseases
B. using hook-and-loop tape in the clothing industry
C. developing smoke detectors for common use
D. studying coal combustion as an energy source
Answer:
b is the correct answer
do not trust answer one
Explanation:
A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
Answer:
The correct answer is 146 g/mol
Explanation:
Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
Therefore, the molar mass of the compound is 146 g/mol
which element Shows very similar chemical properties to barium?
a water sample is found to have a cl- content of 100ppm as nacl what is the concentration of chloride in moles per liter
Answer:
The concentration of chloride ion is [tex]2.82\times10^{-3}\;mol/L[/tex]
Explanation:
We know that 1 ppm is equal to 1 mg/L.
So, the [tex]Cl^-[/tex] content 100 ppm suggests the presence of 100 mg of [tex]Cl^-[/tex] in 1 L of solution.
The molar mass of [tex]Cl^-[/tex] is equal to the molar mass of Cl atom as the mass of the excess electron in [tex]Cl^-[/tex] is negligible as compared to the mass of Cl atom.
So, the molar mass of [tex]Cl^-[/tex] is 35.453 g/mol.
Number of moles = (Mass)/(Molar mass)
Hence, the number of moles (N) of [tex]Cl^-[/tex] present in 100 mg (0.100 g) of [tex]Cl^-[/tex] is calculated as shown below:
[tex]N=\frac{0.100\;g}{35.453\;g/mol}=2.82\times 10^{-3}\;mol[/tex]
So, there is [tex]2.82\times10^{-3}\;mol[/tex] of [tex]Cl^-[/tex] present in 1 L of solution.
Atomic radius is....
O The tendency for an atom to attract electrons
The energy required to remove an electron
O The energy required to add an electron
O The distance from the nucleus to the last orbital
HELP ME ASAP!
Under the Law of Multiple Proportions, Carbon Dioxide has a ratio of 2.666 g
Oxygen for every 1 g Carbon. Given this, how much oxygen is present in a sample
of carbon dioxide that has 16 g of carbon?
Answer:
In carbon dioxide, on the right, there is 2.666 g of oxygen for every gram of carbon. So the ratio of oxygen in the two compounds is 1:2, a small whole number ratio
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In the acid-base mechanism, the base is a proton acceptor, and the acid is the proton donor. An acid-base reaction is visualized as the reaction in which proton transfer takes place. However, in a nucleophilic substitution reaction, the nucleophile attacks a substrate (usually an electrophile), and the leaving group is removed from the substrate as a weaker nucleophile. The nature of the reactants determines whether a reaction will proceed as an acid-base reaction or a nucleophilic substitution reaction. Classify each reaction as a nucleophilic substitution reaction or an acid-base reaction.
a. CH3CH2O-+CH3Br → CH3CH2OCH3+Br-
b. CH3CH2OH+HCl → CH3CH2Cl+H2O
c. CH3COOH+NaOH → CH3COONa +H2O
d. CH3CH2CH2Br+HCN→CH3CH2CH2CN+HBr
e. CH3CH2OH+KOH→CH3CH2OK +H2O
Answer:
a) nucleophilic
b) Acid-base
c) Acid- base
d) nucleophilic
e) Acid-base
Explanation:
A nucleophilic reaction is one in which a nucleophile attacks a substrate and a leaving group departs from the substrate.
Reactions (a) and (d) are nucleophilic reactions since the Br- is the leaving group in the both reactions.
Reactions (b) (c) and (e) are acid-base reactions since they involve salt and water as products.
A tree frog uses plants or trees for protection from the rain. The frog is protected from the rain and the tree is neither helped nor harmed
Is lead a representative metal or transitional metal?
Answer:
It's a representative metal
Explanation: Transitional metals are metals of various chemical elements and have valence electrons—i.e., electrons that can participate in the formation of chemical bonds.
Antoine Lavoisier correctly characterize as an element?
Please help
What is an element
Answer:
An element is atoms with the same number of protons.
Explanation:
Protons, electrons, and neutrons.
Plz answer me will mark as brainliest
Answer:
Compared to the walls of the right ventricle, the walls of the left ventricles are much thicker.
The plasma carries hormones, which are the body's chemical messengers.
Question 2 of 10 >
Nitrogen and hydrogen combine at a high temperature, in the presence of a catalyst, to produce ammonia,
8H8
N2(g) + 3 H2(g) — 2NH,(8)
Assume 0.170 mol N, and 0.561 mol H, are present initially,
After complete reaction, how many moles of ammonia are produced?
NH,
How many moles of H, remain?
Answer:
Moles of H₂ left = 0.051 mol
Moles of ammonia formed = 0.34 mol
Explanation:
Given data:
Moles of N₂ = 0.170 mol
Moles of H₂ = 0.561 mol
Moles of ammonia formed = ?
Moles of H₂ left = ?
Solution:
Balance chemical equation:
N₂ + 3H₂ → 2NH₃
Now we will compare the moles of ammonia with nitrogen because nitrogen is limiting reactant and limit the yield of ammonia.
N₂ : NH₃
1 : 2
0.170 : 2×0.170 = 0.34 mol
Moles of ammonia formed = 0.34 mol
Moles of H₂ reacted:
N₂ : H₂
1 : 3
0.170 : 3/1×0.170 = 0.51 mol
0.51 moles of hydrogen react with 0.170 moles of nitrogen.
Moles of H₂ left:
Moles of H₂ left = Total - moles reacted
Moles of H₂ left = 0.561 mol - 0.51 mol
Moles of H₂ left = 0.051 mol
A student dissolves of sodium hydroxide in of water in a well-insulated open cup. He that observes the temperature of the water rise from to over the course of minutes. Use this data, and any information you need from the ALEKS Data resource,
NaOH(s) rightarrow Na+(aq) + OH-(aq)
You can make any reasonable assumptions about the physical properties of the solution. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
1. Is this reaction exothermic, endothermic, or neither.
2. If you said the reaction was exothermic or endothermic, calculate the amount of neat that was released or absorbed by the reaction in this case.
3. Calculate the reaction enthalpy AW per mole of NaOH.
Answer:
This question is incomplete
Explanation:
This question is incomplete but the answer to (1) and steps involved in calculating (2) and (3) will be discussed in the attachment
1. The reaction is an exothermic reaction because heat was given off. Exothermic reaction is a reaction in which heat is released from a reaction into the surroundings. And according to the question, the student observed that the temperature of the water increased during the course of the minutes.
If 1.02 g of nickel reacted with 750. mL of 0.112 M hydrobromic acid, how much of each will be present at the end of the reaction if you captured the gas in a 2.50 L vessel at 30 C
Answer:
35.1% is percent yield
Explanation:
Full question: Assume no volume change. If you formed 0.0910 atm of gas, what is the percent yield?
The reaction that is occurring is:
Ni + 3HBr → NiBr₃ + 3/2H₂(g)
First, we will determine moles of Ni and HBr to determine limiting reactant and theoretical yield
Using ideal gas law, we can determine the moles of hydrogen formed. Thus, we can find percent yield:
Moles Ni (Molar mass: 58.69g/mol):
1.02g * (1mol / 58.69g) = 0.01738moles Ni
Moles HBr:
0.750L * (0.112mol/L) = 0.084 moles of HBr.
For a complete reaction of the 0.084 moles of HBr you need:
0.084mol HBr * (1 mole Ni / 3 moles HBr) = 0.028 moles of Ni.
As there are just 0.01738 moles of Ni, the Ni is limiting reactant. Assuming a theoretical yield, moles of H₂ produced are:
0.01738moles Ni * (3/2 H₂ / 1 mol Ni) = 0.02607 moles H₂
Now, moles of H₂ produced are:
PV = nRT
PV/RT = n
Where P is pressure (0.0910atm)
V is volume (2.50L)
R is gas constant (0.082atmL/molK)
T is absolute temperature in Kelvin (30°C + 273.15 = 303.15K)
And n are moles
PV/RT = n
0.0910atm*2.50L/0.082atmL/molK*303.15K = n
0.00915 moles = n
And percent yield (Produced moles / Theoretical moles * 100) is:
0.00915 moles / 0.02607moles =
35.1% is percent yieldWhat is the gravitational potential energy, in joules, of a 75 kg person that is 1000.0
meter above the ground? Gravitational acceleration = 9.81 m/s2
Answer:
In this example, a 3 kilogram mass, at a height of 5 meters, while acted on by Earth's gravity would have 147.15 Joules of potential energy, PE = 3kg * 9.81 m/s 2 * 5m = 147.15 J. 9.81 meters per second squared (or more accurately 9.80665 m/s 2 ) is widely accepted among scientists as a working average value for Earth's gravitational pull.
Explanation:
What is the dependent variable? Be specific. *
If a teacher washes the tops of the student
desks with rubbing alcohol daily, the
spread of germs in the classroom may be
diminished.Be specific when you write your answer HELPPPPP I NEED IT ASAP!
In which Earth system does the rock cycle take place?
cryosphere
atmosphere
geosphere
biosphere
Answer:
geosphere
Explanation:
geo means rocks this is the area
hope this helps dude
PLSSS HELP Match each image to the
correct step of meiosis. PLS HELP
Answer:
Explanation:
Here you go!! Hope this helps.
Draw molecules that satisfy the following prompts:
1. All molecules must have a minimum of 12 Carbon atoms and exactly 3 heteroatoms (not carbon or hydrogen atoms).
2. You may not use the same molecule twice for any parts of this question.
4. You do not need to look up solubility information, but the answers must be reasonable (supported by the concepts that we have discussed). Also, the structures must be reasonable (improper structures, e.g. carbon with 5 bonds or oxygen with one bond and no charge, will not receive any credit).
a. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M HCl(aq) and dichloromethane.
b. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M NaOH(aq) and dichloromethane.
c. Draw two non-charged molecules that will be separated using neutral water and dichloromethane and in a separatory funnel.
Answer:
see images attached
Explanation:
Here we are trying to perform solvent extraction. In solvent extraction, there must be an aqueous phase and an organic phase.
One of the species to be separated is extracted in greater concentration in the aqueous phase while the other is extracted in greater concentration in the organic phase.
The phase into which each specie is extracted depends on the nature of the specie.
Two structures are shown in the images attached that will be separated by the methods shown in (a) (b) (c) in the question
How many molecules are there in 985 mL of nitrogen at 0.0 degrees C and 1.00x10^-6 mm Hg?
(It would be better if work or steps to solve problem are given but if not its fine).
Answer:
3.48 x 1013 N2 molecules
step-by-step explanation:
Lets set up our equation first
P = 1.00 x 10-6 mm Hg T = 0.0° C + 273 = 273 K
We are given the V = 985 mL ,
R = 0.0821 L·atm/mol·K
Now use the ldeal gas law, but we are solving n, amount of substanvce
PV = nRT, we will change this equation to ;
n = PV/RT
n = 1.00 x 10-6 mm x 1 atm/760 mm x 985 mL x 1 L/103
mL/
(0.0821 L·atm/mol·K x 273 K) = 5.78 x 10-11 moles N2
nmolecules = 5.78 x 10-11 moles N2 x 6.02 x 1023 N2 molecules/1 mol N2
Level 1 01 Which correctly pairs the outside particles with their charge? A. Electrons: Positive B. Protons: Positive C. Neutrons: Neutral D. Electrons: Negative
Answer:
D. Electrons: Negative.
Explanation:
Hello, happy to help you today!
In this case, by considering the Bohr's atomic model in which atom is composed by a nuclei containing both protons and neutrons which are positively and neutrally charged respectively and surrounding electrons assembled in orbits or levels of energy which are negatively charged in order to provide a balance to the atom, the correct statement is: D. Electrons: Negative. Also consider the Bohr's model on the attached picture.
My best regards to you!
Each molecule of an olefin has at least:
a
one double bond
b
two double bonds
c
three double bonds
d
two or more single bonds
Answer:
a.
Explanation:
One double bond.
For example ethene CH2=CH2
what’s the most abundant isotope of lawrencium
Answer:
266Lr
Thirteen isotopes of lawrencium are currently known; the most stable is 266Lr with a half-life of 11 hours, but the shorter-lived 260Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale.
Explanation:
hopefully that helps you
Which number represetns a coefficient?
2
3
4
7
If 0.4743 moles of H2O are produced, how many grams of VOCl3 will also be produced?
(V2O5 + 6 HCl → 2 VOCl3 + 3 H2O)
Answer:
i hope this helps. sorry if it totally doesn't
Solid calcium chlorate decomposes to form solid calcium chloride and oxygen gas.
Write the balanced chemical equation for the reaction described. Phases are optional.
equation:
Answer:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Explanation:
Chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Balance chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Step 1:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 2
Step 2:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 6
How many F atoms are present in 3.16 moles of BaF2? show work
Answer:
3.80 × 10²⁴ atoms of F
Explanation:
Step 1: Given data
Moles of barium fluoride (BaF₂): 3.16 mol
Step 2: Calculate the moles of fluorine in 3.16 moles of barium fluoride
The molar ratio of BaF₂ to F is 1:2. The moles of F in 3.16 moles of BaF₂ are 2/1 × 3.16 mol = 6.32 mol.
Step 3: Calculate the atoms of F in 6.32 moles of F
We will use Avogadro's number: there are 6.02 × 10²³ atoms of F in 1 mole of atoms of F.
6.32 mol × (6.02 × 10²³ atom/1 mol) = 3.80 × 10²⁴ atom
__________ 5. Chemical equilibrium is the result of A. all of the reactants being converted into products. B. stoppage of further reaction. C. formation of products equal in mass to the mass of the reactants. D. opposing reactions attaining equal rates. E. a loss of pressure in the system.
Answer:
The correct option is C
Explanation:
Chemical equilibrium is a state in which there is no net change in the amount of reactant and products formed over time. This reaction is a reversible reaction, hence the reaction can keep proceeding in either direction until the products formed are equal in mass to that of the reactants or the products been reversed back to the reactants until both sides (product and reactant) achieve equal mass.
Cementation is part of the process of
A. igneous intrusion
B. lithification
C. igneous extrusion
D. metamorphism
SUBMIT
Answer:
The correct answer is b.
Explanation:
hope this helps u
Answer:
Bryna is correct it is B
Explanation: