Answer:
The decreasing in concentration occurs after 69.0s
Explanation:
A first order reaction follows the equation:
Ln [A] = -kt + ln[A]₀
Where [A] is the concentration of the reactant after time t
k is rate constant of the reaction
And [A]₀ is the initial concentration of the reactant
Replacing:
Ln 2.45x10⁻²M = -1.80x10⁻²s⁻¹*t + ln8.48x10⁻²
-3.709 = -1.80x10⁻²s⁻¹*t -2.467
-1.2416 = -1.80x10⁻²s⁻¹*t
69.0s = t
The decreasing in concentration occurs after 69.0s
A solution of 6.2 M H2SO4 is diluted from 2.0 L to 3.0 L. What is the molarity of the resulting solution?
Answer:
Here's link to the answer:
bittuly/3a8Nt8
Explanation:
According to molar concentration, molarity of the resulting solution is 4.32 molar.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substitution in formula M₁V₁=M₂V₂ gives M₂=6.2×2/3=4.32 M.
Learn more about molar concentration,here:
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Use the food web below to answer the following
question.
Frog
Red fox
Grasshopper
Weasel
Goldfinch
Great horned om
Clover
Deer mouse
Which group is not represerted in the food web?
A. producers
B. primary consumers
C. secondary consumers
D. decomposers
Answer:
uhm i believe its D hope i helped
Explanation:
Answer:
D. decomposers
Plutonium is a radioactive material, exposure to which is hazardous to human health, and is one of the few materials that can be used to make a nuclear weapon. The time it takes for half of any initial quantity of plutonium to decay into stable non-radioactive products is roughly:
Answer:
24,000 years
Explanation:
Pls help!
the chemical that is responsible for stopping reaction is called the ____
Answer:
reactant
Explanation:
I watched a chem video and this is what they called it.
Reactants of a combustion reaction include
select all that apply
Fuel
Oxygen
Water
Carbon Dioxide
Answer: fuel and oxygen are reactants.
Explanation:
Answer:
fuel and oxygen
Explanation:
I take test
Which of the following statement is not true?
Answer: 2
Explanation: Greenhouse gases are very important in keeping our planet just right. If we have too many Greenhouse gases it would be too hot, but we can't eliminate all of them or it will be too cold
F or pass? I’m okay with pass
Answer:
pass
Explanation:
pass
how are the functions of a flower's stamen and pistil related to reproduction?
Answer: the essential parts of a flower
Explanation:
are engaged with seed creation. In the event that a blossom contains both useful stamens and pistils, it is known as an ideal bloom, regardless of whether it doesn't contain petals and sepals. On the off chance that either stamens or pistils are deficient with regards to, the blossom is called imperfect.
Compute the percentage of error to the nearest tenth in the student’s calculation if the actual specific heat value for aluminum is 0.9J:g*C.
Complete Question:
1. A block of aluminum with a mass of 140 g is cooled from 98.4°C to 62.2°C with a release of 4817 J of heat. From these data, calculate the specific heat of aluminum.
a. Compute the percentage of error to the nearest tenth in the student's calculation if the actual specific heat value for aluminum is 0.9 J/g°C
Answer:
Percent error = 55.56 %
Explanation:
Given the following data;
Mass = 140 grams
Initial temperature = 62.2°C
Final temperature = 98.4°C
Quantity of heat = 4817 Joules.
To find the specific heat capacity;
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat. m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.dt = T2- T1
dt = 98.4 - 62.2
dt = 36.2°C
Making c the subject of formula, we have;
[tex] c = \frac {Q}{mdt} [/tex]
Substituting into the equation, we have;
[tex] c = \frac {4817}{140*36.2} [/tex]
[tex] c = \frac {4817}{5068} [/tex]
Specific heat capacity, = 0.95 J/g°C
b. To find the percentage error;
Given the following data;
Actual specific heat capacity = 0.9 J/g°C
Experimental specific heat capacity = 0.95 J/g°C
Percent error can be defined as a measure of the extent to which an experimental value differs from the theoretical value.
Mathematically, it is given by this expression;
[tex] Percent \; error = \frac {experimental \;value - actual \; value}{ actual \;value} *100[/tex]
Substituting into the formula, we have;
[tex] Percent \; error = \frac {0.95 - 0.9 }{ 0.9} *100[/tex]
[tex] Percent \; error = \frac {0.5}{0.9} *100[/tex]
[tex] Percent \; error = 0.5556 *100[/tex]
Percent error = 55.56 %
What is so important about DNA? Select all correct answers.
A. DNA is found in all organisms and carries instructions to build those organisms
B. DNA found in one organism probably shares similar instructions found in another species
C. DNA is composed of only four bases that repeat in a sequence that is different for each
species
D. Some organisms don't actually have DNA
E. The DNA of each organism is made out of different types of chemicals
Answer:
A and C
Explanation:
DNA is what makes up you and me and DNA is composed of four bases adenine, guanine, thymine, and cytosine. The others are not true.
You are given a 1.55 g mixture of calcium nitrate and calcium chloride. You dissolve this mixture in 20 mL of water and add an excess of 0.300 M silver nitrate. You collect and dry the resulting precipitate and determine it has a mass of 0.535 grams. Calculate the percent calcium chloride in the original mixture.
Answer:
13.4 (w/w)% of CaCl₂ in the mixture
Explanation:
All the Cl⁻ that comes from CaCl₂ (Calcium chloride) will be precipitate in presence of AgNO₃ as AgCl.
To solve this problem we must find the moles of AgCl = Moles of Cl⁻. As 2 moles of Cl⁻ are in 1 mole of CaCl₂ we can find the moles of CaCl₂ and its mass in order to find mass percent of calcium chloride in the original mixture.
Moles AgCl - Molar mass: 143.32g/mol -:
0.535g * (1mol / 143.32g) = 3.733x10⁻³ moles AgCl = Moles Cl⁻
Moles CaCl₂:
3.733x10⁻³ moles Cl⁻ * (1mol CaCl₂ / 2mol Cl⁻) = 1.866x10⁻³ moles CaCl₂
Mass CaCl₂ -Molar mass: 110.98g/mol-:
1.866x10⁻³ moles CaCl₂ * (110.98g/mol) = 0.207g of CaCl₂ in the mixture
That means mass percent of CaCl₂ is:
0.207g CaCl₂ / 1.55g * 100 =
13.4 (w/w)% of CaCl₂ in the mixtureWhat happens as you decrease the temperature of a solution?
A.
The number of solute particles increases.
B.
The number of solute particles decreases.
C.
The rate of dissolution increases.
D.
The rate of dissolution decreases.
E.
The temperature has no effect on the rate of dissolution.
Answer:
D is the answer
Explanation:
What is a chemical bond?
What effect could the pollution of Groundwater have on a nearby River, Lake or Stream?
Answer:
please give me brainlist and follow
Explanation:
Contamination of ground water can result in poor drinking water quality, loss of water supply, degraded surface water systems, high cleanup costs, high costs for alternative water supplies, and/or potential health problems. The consequences of contaminated ground water or degraded surface water are often serious.
What is the mass of sulfuric acid, H2SO4, that is contained in 2.0 L of a 5.85 M solution ?
A-1147.44 grams
B- 0.12 grams
C-11.7 grams
D-98.07 grams
N3- ion name pls help!!
Answer:
N with a charge of (-3) is nitride
Explanation:
Most of the world’s energy comes from what three sources?
These energy sources are called ______________fuels and they are _____________________ resources.
Answers:
Most of the world’s energy comes from what three sources?
Oil, coal, and gas.
These energy sources are called fossil fuels and they are non-renewable resources.
Fuel type: oil
How it's formed: from the remains of ancient marine organisms
Its uses: transportation, industrial power, heating and lighting, lubricants, petrochemical industry, and use of by-products
Fule type: coal
How it's formed: when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial
Its uses: electricity generation, metal production, cement production, chemical production, gasification, and other industrial uses
Fuel type: gas
How it's formed: decomposed organic matter mixed with mud, silt, and sand on the seafloor
Its uses: heating & cooling buildings, cooking foods, fueling vehicles, and electricity generation
The particles of a substance lose energy and change from
a disordered structure with large distances between the particles to
a loosely ordered state.
Which change of state is described?
Answer:
A Liquid
Explanation:
structure with large distance (gas) than goes to a loosely ordered state (liquid)
I hope this helps
What is the mass of 925.4 L of hydrogen gas at STP?
Answer:
If this is an idea gas then 1mol takes up 22.4L.
So, knowing how many L you have you can figure out how many mole syou have by doing a simple equation:
[tex]\frac{1mol}{y} =\frac{22.4L}{925.4L}[/tex]
Solve for y.
Then, since you know how many moles you have use the ptable https://ptable.com/#Properties to figure out the mass in grams.
NOTE: The ptable tells you that 1mol of H = 1g.....so this should be an easy calculation :) enjoy
5 The atoms of a certain element each contain 36 protons and 8 valence electrons. Which
statement correctly identifies this element and describes its chemical reactivity? (8.58)
A The element is krypton, Kr, and it is not very reactive.
B The element is chlorine, Cl, and it is highly reactive.
C The element is krypton, Kr, and it is highly reactive.
D The element is chlorine, Cl, and it is not very reactive.
Answer:
dfdfaxc b
Explanation:
A gaseous mixture contains 5.0 moles of nitrogen and 10.0 moles of helium . What is the total pressure if the temperature is 25 degrees C and the volume is 3.0 L? a) 122 atm
B) 56 atm
d) 2.0 atm
C)3.0 atm
Answer:
A) 122 atm
Explanation:
PV = nRT
Solve for P --> P = nRT/V
n = 10.0 mol + 5.0 mol = 15.0 mol
R = 0.08206 L atm / mol K
T = 25 + 273 = 298 K
V = 3.0
P = (15.0)(0.08206)(298) / (3.0) = 122 atm
Which substance cannot be separated or broken down into simpler substances by chemical means?
table salt
gold wire
candle wax
water vapor
Answer: Gold Wire
Explanation:
Out of all of these options only gold wire is an element, elements are pure and cannot be broken down by any chemical means
hope it helped, good luck :)
calculate how many Liters of 0.50 M silver nitrate solution you will need to provide the 2.4x10^-3 moles of silver nitrate
Answer:
4.8x10⁻³ Liters are required
Explanation:
Molarity is an unit of concentration in chemistry defined as the ratio between moles of solute (In this case, silver nitrate) and liters of solution.
The 0.50M solution contains 0.50 moles of silver nitrate per liter of solution.
To provide 2.4x10⁻³ moles Silver nitrate are required:
2.4x10⁻³ moles * (1L / 0.50 moles) =
4.8x10⁻³ Liters are requiredhow to obtain pure aluminium oxide from sodium aluminate. pls help.
Answer:
By Bayer process.
Explanation:
In the Bayer process, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution (caustic soda) at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as sodium aluminate (primarily [Al(OH)4]−) in an extraction process.
What do glycine, leucine, and lysine all have in common?
They are the building blocks of proteins.
They have an important role in the heart.
They have a role in the functioning of the stomach.
They store equal amounts of energy in their bonds.
Answer:
a, they are the building blocks of proteins.
Explanation:
hope this helps!
~mina
Answer:
A. They are the building blocks of proteins.
(Photo for proof at the bottom.)
Explanation:
Glycine, leucine, and lysine are all amino acids. There are 20 different kinds of amino acids, including the 3 mentioned here. Different amino acids bond together to form different structures, depending on how many there are. Generally, 50 or more amino acids bonded together makes a protein. But there are some exceptions. Amino acids (including glycine, leucine, and lysine) are the building blocks of proteins.
Here's a photo of Edge incase you're doubtful.
Please click the heart if this helped.
What do all electrolytes have in common?
They have low melting points.
They are polar molecules.
They have mobile ions in solution.
They are compounds of carbon.
On a certain hot day the atmospheric pressure was 1 atm and the temperature was 37°C. On this day 1 L sample of atmospheric gases was collected and analyzed. It was found to contain among other gases 9.38 x 10-3 mol of O2 gas, 2.46 x 10-8 mol of H2 gas and 1.79 x 10-4 mol of water vapor. If you put these amounts of the three gases in a sealed 1L tank at 1 atm and 37°C, will the combustion of hydrogen gas be spontaneous at these conditions?
Answer:
Yes, the combustion of hydrogen is spontaneous from the given conditions.
Explanation:
Let look at the reaction:
[tex]2H_2_{(g)} + O_2_{(g)} \to 2H_2O_{(g)}[/tex]
[tex]K_p = \dfrac{[P(H_2O)]^2}{[P(H_2)^2\times P(O_2)]} ----- (1)[/tex]
The total pressure of the tank = 1 atm
[tex]\mathtt{Pressure \ of \ the \ gas = moles \ fraction \of \ gas \times total \ pressure}[/tex]
Thus, pressure of [tex]O_2[/tex] gas = [tex]\dfrac{9.38 \times 10^{-3} }{(9.38 \times 10^{-3} + 2.46 \times 10^{-8} + 1.79 \times 10^{-4}} \times 1 atm[/tex]
[tex]P(O_2) = 0.9813 atm[/tex]
Pressure of [tex]H_2O[/tex] gas =[tex]\dfrac{1.78 \times 10^{-4}}{9.38 \times 10^{-3} + 2.46 \times 1)^{-8} + 1.78 \times 10^{-4}} \times 1 \ atm[/tex]
Pressure of H_2 gas = [tex]2.573 \times 10^{-6} \ atm[/tex]
From equation (1);
[tex]K_p = \dfrac{(0.0187)^2}{(2.573 \times 10^{-6})^2 \times (0.913) } \\ \\ K_p = 5.383 \times 10^7[/tex]
So, applying the equation:
[tex]\Delta G^0 = -RT In K_p \\ \\ = -8.314 \times (300)K \times IN(5.383 \times 10^7) \\ \\ = -45880.109 J \\ \\ = -45.800 \ kJ\\ \\[/tex]
Thus;
[tex]\Delta G^0 < 0[/tex]
Thus, Yes the combustion of hydrogen is spontaneous from the above conditions. From thermodynamics, we realize that assuming ∆G is negative, the reaction is spontaneous. Again we understand that ∆G=∆H-T∆S. However, for combustion, water will definitely be formed.
Finally, we can conclude that;
∆H is negative;
∆S is positive; &
∆G is also negative.
Thus, from above, we conclude combustion of hydrogen is spontaneous.
The combustion of hydrogen gas with the oxygen gas for the formation of the water vapor is a spontaneous reaction.
How do we know reaction is spontaneous?To know about the condition that the given reaction is spontaneous or not we will use the below equation and must get the negative value:
ΔG° = -RTlnKp, where
R = universal gas constant
T = temperature
Kp = partial pressure constant
Firstly we have to calculate the value of Kp.
Given chemical reaction is:
2H₂(g) + O₂(g) → 2H₂O(g)
Value of Kp for the given reaction is:
Kp = [p(H₂O)]² / [p(H₂)]².[p(O₂)]
Partial pressure will be calculated as:
p = mole fraction × total pressure
Given that total pressure of gas = 1atm
p(H₂O) = (1.79×10⁻⁴ / 1.79×10⁻⁴+2.46×10⁻⁸+9.38×10⁻³) × 1 = 0.0187
p(H₂) = (2.46×10⁻⁸ / 1.79×10⁻⁴+2.46×10⁻⁸+9.38×10⁻³) × 1 = 2.573 × 10⁻⁶
p(O₂) = (9.38×10⁻³ / 1.79×10⁻⁴+2.46×10⁻⁸+9.38×10⁻³) × 1 = 0.913
Putting all these values on the equation of Kp, we get
Kp = (0.0187)² / (2.573 × 10⁻⁶)²(0.913) = 5.383 × 10⁷
Now putting values in the first equation we get,
ΔG° = -(8.314)(300)ln(5.383 × 10⁷)
ΔG° = -45,800 kJ
Hence, given reaction is spontaneous.
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Jess is baking a cake. Part of the recipe has Jess mix butter and water. He notices that the two substances don't mix. He is confused because water and butter are both covalent compounds. Explain why the butter and water are NOT mixing in the bowl.
Answer:
butter and water don't mix because water is polar and butter is nonpolar
Explanation:
for them to be able to mix they would need to be both polar or both nonpolar.
Which of the following pictures is a chemical change, and which is a
physical change? Explain in the boxes next to the picture.
Plz explain
Answer:
left is chemical because its chemicals, and right is physical because the ice cream is melting and thats physical
Explanation:
Why might changes to an environment cause an organism’s population to decrease?