Answer: -40
Explanation: Percent error is calculated by subtracting the value you actually recieved from the literature value (175 in your case) SO your answer should be 135-175=-40.
When 14.8 g KOH is dissolved in 85.6 g of water in a coffee-cup calorimeter, the temperature rises from 19.3 °C to 32.76 °C. What is the enthalpy change per gram of potassium hydroxide dissolved in the water?
Answer:
This question is incomplete, the complete question is; assuming that the solution has a specific heat of 4.18 J/g°C
The answer is 381.67 J/g
Explanation:
Enthalpy change denoted by ΔH can be calculated using the formula;
ΔH = m × c × ΔT
Where; m= mass of reactants
c= specific heat
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 32.76 - 19.3
ΔT = 13.46 °C
mass of reactants= 85.6 + 14.8 = 100.4g, c = 4.18J/g°C
Hence; ΔH = m × c × ΔT
ΔH = 100.4 × 4.18 × 13.46
ΔH = 5648.78J
Enthalpy change per gram of potassium hydroxide dissolved in the water is;
ΔH = 5648.78/14.8
ΔH = 381.67 J/g
The enthalpy change per gram of potassium hydroxide dissolved in the water is 382 J/g
How to determine the heat Mass (M) = 14.8 + 85.6 = 100.4 gInitial temperature (T₁) = 19.3 °C Final temperature (T₂) = 32.76 °CChange in temperature (ΔT) = 32.76 – 19.3 = 13.46 °C Specific heat capacity (C) = 4.184 J/gºC Heat (Q) =?
Q = MCΔT
Q = 100.4 × 4.184 × 13.46
Q = 5654.19 J
How to determine the enthalpy change ΔHHeat (Q) = 5654.19 JMass of KOH (m) = 14.8 gEnthalpy change (ΔH) =?ΔH = Q / g
ΔH = 5654.19 / 14.8
ΔH = 382 J/g
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which of the following best describes a non metal
Answer:
-a nonmetal is a substance that lacks the characteristics of a metal.
-Seventeen elements are generally classified as nonmetals: most are gases (hydrogen, helium, nitrogen, oxygen, fluorine, neon, chlorine, argon, krypton, xenon and radon); one is a liquid (bromine); and a few are solids (carbon, phosphorus, sulfur, selenium, and iodine).
An advertisement for a new fish food claims that lab studies show that fish grew three inches in three weeks while eating the food. Travis wondered if the food was worth the extra cost.
Answer: To evaluate the claim in the advertisement, Travis should look at the data for the control group to see how much the fish grew without the new food.
Explanation:
Is gasoline evaporated, gasoline, burned water frozen and water heated up a chemical change
Answer:
as gasoline is evaporated, this gasoline still remains as gasoline but in gaseous form when gas is being burned .
The measurement 3.8 x 10^3 g could also be written as
Right now it's written in scientific notation, so you can just move the decimal place in 3.8 to the right 3 times (as it is times 10 to the third power) to get 3,800g.
The measurement 3.8 x 10³ grams could also be written as 3.8 kilograms.
What is a unit of measurement?A unit of measurement is a specified magnitude of a quantity that is established and used as a standard for measuring other quantities of the same kind. It is determined by convention or regulation.
As given in the problem we have to convert the measurement of 3.8 x 10³ grams into some different units,
1000 grams = 1 kilograms
1 gram = 1 /1000 kilograms
3.8 x 10³ grams = 3.8 x 10³ ×1 /1000 kilograms
=3.8 kilograms
Thus, the measurement 3.8 x 10³ grams could also be written as 3.8 kilograms.
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A recipe calls for 12 ounces of cocoa powder. All you have are measuring cups. If cocoa powder weighs 0.652 grams per cm3, how many cups of cocoa powder will you need? (1 Tbsp = 15 mL; 1 cup = 16 Tbsp; 1 mL = 1 cc3; 28.4 g = 1 oz.)
Answer:
1 and a half cups
Explanation:
12 ounces is equivalent to 1.5 cups
The noble gas electron configuration for Ca2+ ion is identical with:______.
A. Ne.
B. Kr.
C. Ca.
D. Ar.
Answer:
D. Ar.
Explanation:
The electron configuration of the atom reflects how the electrons are distributed among the various atomic orbitals. Just as for neutral atoms, we use the Pauli exclusion principle and Hund’s rule in writing the ground-state electron configurations of cations and anions.
Ions formed from atoms of most representative elements have the noble-gas outer electron configuration of ns²np⁶. In the formation of a cation from the atom of a representative element, one or more electrons are removed from the highest occupied n shell. The electron configuration of calcium and its ion is as follows:
Ca: [Ar]4s² Ca²⁺ : [Ar]
How many atoms are in one body-centered cubic unit cell of a metal?
A) 1.
B) 2.
C) 3.
D) 4.
Answer:
Option B - 2
Explanation:
In Crystal lattices, there are different types of unit cells namely;
- Hexagonal Closest Packed (HCP)
- Face Centred Cubic (FCC)
- Body Centred Cubic (BCC)
- Simple Centred Cubic (SC)
Now, each of them have a coordination number and also number of atoms per unit cell.
For this question, we are restricted to the body-centered cubic (bcc) unit cell which has a coordination number of 8 and contains 2 atoms per unit cell.
Answer:
B) 2.
Explanation:
They have 8 1/8 atoms on the edge that add to get 1 atom. Plus one whole atom inside. 1+1=2
A cube has an edge length of 9 cm .
If it is divided up into 1-cm cubes, how many 1-cm cubes would there be?
Answer:
9^3 i think so like 279
Explanation:
blah
Based on your observations of the laboratory assignment(s) that produced gases, can you conclude
that the same gas was produced in each assignment? Briefly explain.
Answer:
With the use of same chemicals, same gas will be produced while the use of different chemicals, different gases will be produced.
Explanation:
The same gas was produced in each assignment if the same chemicals are mixed with each other while different gases were produced in each assignment when different chemicals are allowed to mix. If every time, same chemicals and same concentration of chemicals are mixed together, the result will be the same means production of same gas but if different chemicals are allowed to mix, then the product will be the production of different gases.
What has 2 protons and 2 neutrons in the center of the atom
Answer:
HELIUM
Explanation:
HELIUM HAS 2 PROTON I
Which device involves the use of plasma in technology? arc welder diesel engine incandescent lightbulb battery-operated flashlight
Answer:
arc welder involves use of plasma in technology
The device involves the use of plasma in technology is "arc welder"
What is plasma ?The 4th phase of matter, after solid, liquid, as well as gas, often been referred to as plasma. Inside a particular substance that is solid, liquid, or even gaseous, the electrons typically stick with almost the unique atomic nucleus.
What is arc welder?Using electricity to generate sufficient heat to dissolve metal as well as then allowing the melted metals to cool, arc welding would be a technique for joining metals together.
Arc welding employs the plasma technology principle because the gas would be ionized.
Therefore, the correct answer will be option (a).
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PLEASE HELP(DUE IN 10 Minuets)
A change in the number of neutrons in an atom will change an isotope. What will happen when the number of protons changes in an atom?
An atom with a mass number of 27 has 14 neutrons. What element is the atom?
Answer:
aluminum i think
Explanation:
A 4.00 (±0.01) mL Class A transfer pipet is used to transfer 4.00 mL of a 0.302 (±0.004) M Cu2+ stock solution to a 100.00 (±0.08) Class A volumetric flask. Deionized water is used to bring the flask to volume. Calculate the concentration of the diluted soluion in the volumetric flask and report its absolute uncertainty.
Answer:
concentration of diluted solution = 0.0125 ( ± 0.0002)M
Uncertainty = ± 0.0002
Explanation:
Given that
Initial volume of Cu2+ = 4.00 (±0.01) mL
Initial molarity 0f Cu2+ = 0.302 (±0.004) M
transferred to 100.00 (±0.08) Class A volumetric flask
first we get amount of water added
100.00 (±0.08) - 4.00 (±0.01) = 96 ± (0.09)
Now according to law of dilution
The concentration of Cu2+ after adding water
M1V1 = M2V2
we substitute
0.302 (±0.004) * 4.00 (±0.01) = x * 96 ± (0.09)
Now the multiplication of two digits with uncertainty is
(0.004/0.302) * 100 = 1.32% ; (0.01/4.00) * 100 = 0.25%
= [0.302 ( ± 1.32% )] * [ 4.00 ± (0.25%)]
= 1.208 ±(1.57%)
1.57/100 * 1.208 = 0.0189
so
= (1.208 ± 0.0189)
now substitute in our previous equation
1.208 ± (0.0189) = x * 96 ± (0.09)
x = 1.208 ± (0.0189) / 96 ± (0.09)
{ 0.09/96 * 100 = 0.094% }
so x = 1.208 ± (1.57%) / 96 ± (0.094% )
x = 0.0125 ± ( 1.664)
now( 1.664/100 * 0.0125)
= ± 0.000208
Hence
concentration of diluted solution = 0.0125 ( ± 0.0002)M
Uncertainty = ± 0.0002
A factor that does no change in an experiment is the.
a. Controlled variable
b. Data
c. Inconstant
d. Independent variable
Answer:
A. Controlled variable
Explanation:
a controlled variable or a constant variable is a variable that doesnt change during an experiment
The scientific method is great, but how do you think we answer the questions which cannot be tested with an experiment?
Answer:
We do something called hypothesis
Answer:
1. Make an observation.
2. Ask a question.
3. Propose a hypothesis.
4. Make predictions.
5. Test the predictions.
6. Iterate.
and if it can't be trsted the you did something wrong
Explanation:
The scientific method
At the core of biology and other sciences lies a problem-solving approach called the scientific method. The scientific method has five basic steps, plus one feedback step:
Make an observation.
Ask a question.
Form a hypothesis, or testable explanation.
Make a prediction based on the hypothesis.
Test the prediction.
Iterate: use the results to make new hypotheses or predictions.
The scientific method is used in all sciences—including chemistry, physics, geology, and psychology. The scientists in these fields ask different questions and perform different tests. However, they use the same core approach to find answers that are logical and supported by evidence.
Scientific method example: Failure to toast
Let's build some intuition for the scientific method by applying its steps to a practical problem from everyday life.
what are we referring to when we talk about the position of an object
Explanation:
The location of a body with reference to a given point.
You should run as an experiment several times to make sure your results are consistent. in the preceding phrase , what does consistent mean
Answer:
To get a final result of experiments, an experiment is repeated several times and the result is noted every time to make sure the results are consistent.
Here the "consistent" meaning is either "same" or "nearby". Consistent results are required in experiments that show constant relation of an experiment to the same principles and the result is not different when performed the same experiment several times.
When performing the same experiment several times, the end result of each experiment should consistent means adhered to the same principle for a successful experiment.
What is Avogadro's number?
the number of atoms in exactly 14.00 g of carbon-12
the number of atoms in a kilogram of any substance
the number of atoms, molecules, ions, formula units, or other particles in a mole of a substance
the number of atoms, molecules, ions, formula units, or other particles in a gram of a substance
Answer:
C
Explanation:
its not A since its actually the atoms in exactly 12g of crabon-12
-not B since its grams not kilograms
-not D since it says "gram" which would mean that we measure the particles in a gram instead of a mole
Avogadro's number is the number of atoms, molecules, ions, formula units, or other particles in a mole of a substance. Therefore, option (c) is correct.
What is Avogadro's number?The Avogadro constant commonly denoted [tex]N_A[/tex] is the proportionality factor that the number of constituent particles such as molecules, atoms, or ions in one mole of a sample.
Avogadro's number is a constant with an exact value of 6.022 × 10²³ reciprocal moles. Avogadro's number is named by Stanislao Cannizzaro after the Italian scientist Amedeo Avogadro, who explained it four years after Avogadro's death.
The numerical value of the Avogadro constant is in reciprocal moles, a dimensionless number known as the Avogadro number. The value of the Avogadro constant, the mass of one mole of a chemical compound, in grams.
It is numerically equal to the average mass of one molecule of the compound in daltons. One dalton is 1/12 of the mass of one carbon-12 atom, which is the mass of one nucleon.
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What is the difference between pure and applied chemistry?
Answer:
Explanation:
The major difference between pure and applied chemistry is the purpose and intent of the study.
Pure chemistry deals with the study of matter, matter transformations, and interactions between the different materials of the world, for only the sake of gaining empirical knowledge about the various substances that exist in the world. It does not really seek to apply this knowledge to do anything industrial.
Applied chemistry is the study of chemistry with the aim of utilizing this knowledge to solve the various problems that man faces. This approach of study is not for knowledge sake alone, rather it is for industrial application
The major difference between pure and applied chemistry is the purpose and intent of the study.
Pure chemistry deals with the study of matter, matter transformations, and interactions between the different materials of the world, for only the sake of gaining empirical knowledge about the various substances that exist in the world. It does not really seek to apply this knowledge to do anything industrial.
Applied chemistry is the study of chemistry with the aim of utilizing this knowledge to solve the various problems that man faces. This approach of study is not for knowledge sake alone, rather it is for industrial application.
Thus,the major difference between pure and applied chemistry is the purpose and intent of the study.
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write the number in scientific notation 1123
The best thermometer to use where temperatures drop below -39°C (-38.2°F) is:_______.
Answer:
The best thermometer to use for this temperature is the alcohol-in-a -glass thermometer.
Explanation:
The alcohol thermometer is a type of thermometer which uses ethanol as its thermometric liquid. This has some advantages at low temperatures because ethanol freezes at about −114.9 °C that is (−174.82 °F).
Due to its low freezing point, it can still function effectively as a thermometric liquid, expanding and contracting properly based on the applied heat, when dealing with temperature measurements that are at about -38.2°F.
13. Adding up all of the
of all of the individual atoms within one molecule of a compound will determine the molecular mass of the compound.
A. atomic numbers
B. electrons
C. atomic masses
D. protons
Which is the formula mass of (NH4)2SO4?
0 96.07 amu
114.12 amu
O 116.17 amu
132.17 amu
Answer:
D. 132.17 amu
Explanation:
The formula mass of a compound can be determined from the formula of the compound thus, from the number each elements present. The formula mass of (NH₄)₂SO₄ is 132.17 amu.
What is formula mass?
Formula mass of a compound is the mass calculated from its formula. Each elements has a definite mass called its atomic mass expressed in g/mol or amu.
Mass number of an element is the sum of number of its protons and neutrons. The actual mass of an element is calculated with respect to the mass of 1/12th of Carbon-12 and it is called relative mass.
Here, the atomic mass of N = 14.006 amu
mass of H = 1.008 amu.
There are 4 hydrogen thus 4 × 1.008 = 4.008 u.
The mass of two units of NH₄ is = (14.006 + 4.008) × 2
= 36.028 u.
Atomic mass of sulfur = 32.6 amu
atomic mass of oxygen = 15.9 amu.
Thus for 4 oxygens = 15.9 × 4 = 63.6 u
The mass of SO₄ unit = 32.06 + 67.6 = 96.2u
Thus the total mass of (NH₄)₂SO₄ = 96.2 + 36.028
= 132.17 amu
Hence, the formula mass of (NH₄)₂SO₄ is 132.17 amu. Thus, option D is correct.
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Convert 542 nanograms to grams.
g.
Answer:
542 nanograms to grams = 5.42E-7g
Explanation:
during a rainy spring, where are you most likely to find surface runoff
Answer:On a sloped parking lot
Explanation:
Pure water can be consumed in a chemical reaction, resulting in the formation of a new
product. Refer to paragraph four. What type of change is this?
A. A physical change
B. A chemical change
C. A mixture change
D. A compound change
Give the name of HI as an acid and as a binary compound
Answer:
HI is a diatomic molecular compound known as hydrogen iodide or hydroiodic acid. It is a strong acid.