The answer is O II only.
I: Calculation errors would be considered a valid source of error in a laboratory experiment. If the calculations made during the experiment are incorrect, it can affect the accuracy of the results.
II: Inability to calibrate measuring devices would NOT be considered a valid source of error in a laboratory experiment. Calibrating measuring devices is an essential step in any experiment to ensure that the measurements being taken are accurate. If the measuring devices are not calibrated correctly, the results of the experiment will be invalid.
III: Using the wrong solution for a reaction would be considered a valid source of error in a laboratory experiment. If the wrong solution is used, the results of the experiment may not be accurate.
Therefore, II is the only option that would NOT be considered a valid source of error in a laboratory experiment.
The answer is O II only.
I: Calculation errors would be considered a valid source of error in a laboratory experiment. If the calculations made during the experiment are incorrect, it can affect the accuracy of the results.
II: Inability to calibrate measuring devices would NOT be considered a valid source of error in a laboratory experiment. Calibrating measuring devices is an essential step in any experiment to ensure that the measurements being taken are accurate. If the measuring devices are not calibrated correctly, the results of the experiment will be invalid.
III: Using the wrong solution for a reaction would be considered a valid source of error in a laboratory experiment. If the wrong solution is used, the results of the experiment may not be accurate.
Therefore, II is the only option that would NOT be considered a valid source of error in a laboratory experiment.
URGENT PLZ HELP
Which of the following statements is true?
a. In an endothermic process heat is transferred from the surroundings to the
system.
b. In an exothermic process heat is transferred from the surroundings to the
system.
C. The surroundings will feel cooler in an exothermic process.
d. The surroundings will feel warmer in an endothermic process.
Answer:
A.
Explanation:
In an endothermic reaction heat is applied.
In an endothermic process, heat is transferred from the surroundings to the system.
What are endothermic and exothermic processes?
An exothermic process is one that gives off heat. This heat is transferred to the surroundings. An endothermic process is one in which heat has to be supplied to the system from the surroundings.
The endothermic process is a term that describes a reaction where the system absorbs the energy from its surrounding in the form of heat. A few examples of the endothermic process are photosynthesis, evaporating liquids, melting ice, etc.
The exothermic reaction is the opposite of an endothermic reaction. It releases energy by light or heat to its surrounding. A few examples are neutralization, burning of a substance, reactions of fuels, etc.
Hence, option A is the correct answer.
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A 5.0 g sample of a pesticide was decomposed with metallic sodium in alcohol, and the liberated chloride ion was precipitated with AgCl. Express the results of this analysis in terms of percent DDT (C14H9Cl5, molar mass, 354.72 g/mol)) based on the recovery of 0.1606 g of AgCl
Answer:
1.59%
Explanation:
First, we convert 0.1606 g of AgCl into moles, using its molar mass:
0.1606 g ÷ 143.32 g/mol = 1.12x10⁻³ mol AgClThen we convert the calculated moles of Cl (equal to AgCl moles) into moles of DDT:
1.12x10⁻³ mol Cl * [tex]\frac{1molDDT}{5molCl}[/tex] = 2.24x10⁻⁴ mol DDTNow we convert 2.24x10⁻⁴ moles of DDT into grams, using its molar mass:
2.24x10⁻⁴ mol DDT * 354.48 g/mol = 0.0794 gFinally we calculate the percentage of DDT in the sample:
0.0794 g / 5.0 * 100% = 1.59%Basic Stoichiometry
Part 1: Mole ←→ Mass Conversions
Choose 2: Convert the following number of moles of chemical into its mass in grams.
1. 0.436 moles of (NH4)Cl = ______g
2. 0.50 moles of Ca(NO3)2 = ______g
Choose 2: Convert the following masses into their corresponding number of moles.
3. 23.5 g of NaCl = ______moles
4. 79.9 g of KMnO4 =______moles
5) The combustion of a sample of butane, C4H10 (lighter fluid), produced 2.46 grams of water.
Answer:
1. 23.3 g
2. 82 g
3. 0.402 mol
4. 0.506 mol
Explanation:
We can convert moles (n) to mass (m) using the following expressions that include the molar mass (M).
n = m/M
m = n × M
1. The molar mass of NH₄Cl is 53.49 g/mol.
m = 0.436 mol × 53.49 g/mol = 23.3 g
2. The molar mass of Ca(NO₃)₂ is 164.09 g/mol.
m = 0.50 mol × 164.09 g/mol = 82 g
3. The molar mass of NaCl is 58.44 g/mol.
n = 23.5 g/(58.44 g/mol) = 0.402 mol
4. The molar mass of KMnO₄ is 158.03 g/mol.
n = 79.9 g/(158.03 g/mol) = 0.506 mol
how can landforms be weathered?
Answer:
they can become smaller or start fall apart or aroud
Explanation:
LEVEL 3
Write the correct order
of letters to the finish line.
A E B E C
Example:
ABCGH
G
H
N
eza
Not correct
Convert 6.62 X 10^23 atoms to moles
Answer:
1.099
Explanation:
Hope this helps
Answer:
1.09944660051578e-23
Explanation:
What is the formula for sodium selenide?
plz, help me I'm so confused!
(this is also science)
Answer:
Well, there is no photo...
Explanation:
Provide a balanced molecular equation, total ionic, and net ionic equation for sodium phosphate and zinc acetate.
Answer: Balanced molecular equation :
[tex]2Na_3PO_4(aq)+3(CH_3COO)_2Zn(aq)\rightarrow 6CH_3COONa(aq)+Zn_3(PO_4)_2(s)[/tex]
Total ionic equation:
[tex]6Na^+(aq)+3PO_4^{2-}(aq)+6CH_3COO^-(aq)+3Zn^{2+}(aq)\rightarrow 6CH_3COO^-(aq)+6Na^+(aq)+Zn_3(PO_4)_2(s)[/tex]
The net ionic equation:
[tex]2PO_4^{3-}(aq)+3Zn^{2+}(aq)\rightarrow Zn_3(PO_4)_2(s)[/tex]
Explanation:
Complete ionic equation : In complete ionic equation, all the substances that are strong electrolyte are present in an aqueous state as ions.
Net ionic equation : In the net ionic equations, we are not include the spectator ions in the equations.
Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.
When sodium phosphate and zinc acetate then it gives zinc phosphate and sodium acetate as product.
The balanced molecular equation will be,
[tex]2Na_3PO_4(aq)+3(CH_3COO)_2Zn(aq)\rightarrow 6CH_3COONa(aq)+Zn_3(PO_4)_2(s)[/tex]
The total ionic equation in separated aqueous solution will be,
[tex]6Na^+(aq)+2PO_4^{3-}(aq)+6CH_3COO^-(aq)+3Zn^{2+}(aq)\rightarrow 6CH_3COO^-(aq)+6Na^+(aq)+Zn_3(PO_4)_2(s)[/tex]
In this equation, and are the spectator ions.
By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.
The net ionic equation will be,
[tex]2PO_4^{3-}(aq)+3Zn^{2+}(aq)\rightarrow Zn_3(PO_4)_2(s)[/tex]
An ideal gas in a sealed container has an initial volume of 2.80 L. At constant pressure, it is cooled to 18.00 °C, where its
final volume is 1.75 L. What was the initial temperature?
Ti =
'c
Answer:
[tex]T_1=-91.18\°C[/tex]
Explanation:
Hello there!
In this case, given the T-V variation, we understand it is possible to apply the Charles' law as shown below:
[tex]\frac{T_1}{V_1}= \frac{T_2}{V_2}[/tex]
Thus, since we are interested in the initial temperature, we can solve for T1, plug in the volumes and use T2 in kelvins:
[tex]T_1= \frac{T_2V_1}{V_2}\\\\T_1= \frac{(18.00+273.15)K(1.75L)}{(2.80L)}\\\\T_1=182K-273.15\\\\T_1=-91.18\°C[/tex]
Best regards!
how many grams are in 6.8L of Oxygen gas (O2) at STP
Answer:
9.7 g
Explanation:
From the question,
Note: The molar volume of all gas at stp is 22.4 dm³ or 22.4 L
1 mol of oxygen gas (O₂) at stp = 22.4 dm³
X mole of oxygen gas (O₂) at stp = 6.8 L
X = (1 mol×6.8 L)/22.4 L
X = 0.3036 mol.
But,
Number of mole (n) = mass (m)/molar mass (m')
n = m/m'
m = n×m'.................. Equation 2
Where n = 0.3036 mol, m' = 32 g/mol
Substitute into equation 2
m = 0.3036×32
m = 9.7 g
The _______________________________________ of a plant cell are where photosynthesis takes place.
Answer:
chloroplast
Explanation:
Answer:
chloroplasts
Explanation:
The electric field around a positive charge will:
how is acid different from base
N2 + 3H2 → 2NH3
How many moles of hydrogen, H2, are needed to react with 3.5 moles of nitrogen, N2?
Answer:
10.5 got it!!!!
When copper is heated with an excess of sulfur, copper(l) sulfide is
formed. In a given experiment, 0.0970 moles of copper was heated
with excess sulfur to yield 5.59 g copper(1) sulfide. What is the
percent yield?
Answer:
72.4%
Explanation:
Step 1: Write the balanced equation
2 Cu + S ⇒ Cu₂S
Step 2: Calculate the theoretical yield, in moles, from 0.0970 moles of Cu
The molar ratio of Cu to Cu₂S is 2:1.
0.0970 mol Cu × 1 mol Cu₂S/2 mol Cu = 0.0485 mol Cu₂S
Step 3, Convert the theoretical yield to mass
The molar mass of Cu₂S is 159.16 g/mol.
0.0485 mol × 159.16 g/mol = 7.72 g
Step 4: Calculate the percent yield
We will use the following expression.
%yield = experimental yield/theoretical yield × 100%
%yield = 5.59 g/7.72 g × 100% = 72.4%
how many liters of 0.150 m hcl would be required to react completely with 8.00 grams of magnesium hydroxide
Answer:
how many liters of 0.150 m hcl would be required to react completely with 8.00 grams of magnesium hydroxide
Explanation:
please give me brainlist and follow
What must happen in order for water to change state?
A. It must maintain its thermal energy level.
B. It must absorb or release energy.
C. It must be insulated.
D. It must convert thermal energy to solar energy.
Answer:
B
Explanation:
if it releases energy it becomes a solid(Solid)
if it absorbs energy it becomes a gas(Water Vapor)
17. The equation below represents a chemical reaction that occurs in living cells.
CoH1206 + 602 -- 6002 + 6H20 + energy
How many atoms are represented in the reactants of this equation?
Answer:
36 atoms
Explanation:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energyThe reactants are in the left side of the equation. First we determine how many atoms are there in the C₆H₁₂O₆ molecule:
6 C atoms + 12 H atoms + 6 O atoms = 24 atoms in totalThere are two atoms in a O₂ molecule, and there are 6 O₂ molecules in the equation:
2 * (6 O atoms) = 12 atoms in totalThe total number of atoms in the reactants is
24 + 12 = 36 atomsHow many molecules are there in a candle wax
Answer:
6
Explanation:
Investigation Question: How do organisms get their genes?
THIS ANSWER SHOULD BE 3 OR MORE SENTENCES.
Answer:
from the chromosome..l dont know
1.1
Which of these is NOT an intermolecular force?
A
Covalent bonding
B
Hydrogen bonding
с
London / dispersion forces
Dipole - dipole forces
1.2
London forces are found between ...
A two polar molecules.
B two non-polar molecules.
C a polar molecule and a non-polar molecule.
Da polar molecule and an ionic substance.
(2
1.3 Which of the following compounds have a shape that can be described as
trigonal bipyramidal?
A
CH4
B
PCL5
с
SF6
D
BF3
(2)
1.4
Which of the following have the same molecular geometry?
CO2, H20, BeCl2 and N20
A
CO2, BeCl2 and N2O
B
H20 and N20 only
C
H20, BeCl2 and CO2
CO2 and N20 only
(2)
Answer:
1.1) Covalent bonding
Explanation:
All of the above are intermolecular forces except covalent, which is intramolecular.
1. The octane present in gasoline burns according to the following equation:
2 C8H18 + 25 O2 → 16 CO2 + 18 H2O
(a) How many moles of O2 are needed to react fully with 27.5 moles of octane?
Answer:
[tex]n_{O_2}=343.75molO_2[/tex]
Explanation:
Hello there!
In this case, according to the combustion of octane:
[tex]2C_8H_1_8+25O_2\rightarrow 16CO_2+18H_2O[/tex]
We can see there is a 2:25 mole ratio of octane to oxygen; therefore, we can calculate the moles of oxygen via the following stoichiometric factor:
[tex]n_{O_2}=27.5molC_8H_1_8*\frac{25molO_2}{2molC_8H_1_8} \\\\n_{O_2}=343.75molO_2[/tex]
Best regards!
If a sample of oxygen gas has a pressure of 810 torr at 298 K, what will be its pressure if its temperature is raised to 330K?
Answer:
The pressure is = 897 torr
Explanation:
We use Gay Lussac's Law.
Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. What is the mass, in grams, of 133 mL of ethanol?
[tex]V = \text{133 mL}[/tex]
[tex]\rho = \text{0.789 g/mL}[/tex]
Required:[tex]m[/tex]
Solution:[tex]\rho = \frac{m}{V}[/tex]
[tex]m = \rho V[/tex]
[tex]m = (\text{0.789 g/mL})(\text{133 mL})[/tex]
[tex]\boxed{m = \text{105 g}}[/tex]
Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. 105g is the mass, in grams, of 133 mL of ethanol.
What is mass?In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the force that is applied. The change caused by a force applied is smaller the more mass a body has.
The kilogram, which would be specified as equivalent to 6.62× 10³⁴ joule second in terms of Planck's constant, is the unit of mass inside the International Units System (SI).
density = mass / volume
mass =density× volume
= 0.78× 1.33
=105g
Therefore, 105g is the mass.
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How many grams of carbon dioxide are produced when 100 grams of methane undergoes complete combustion's?
Answer: 1 mol of methane is 16 grams. Therefore, if you have 100 grams of methane, it means that you have 10016=6.25 moles of methane. When you burn 6.25 moles of methane, you produce 6.25 moles of carbondioxide.
Explanation:
How many moles are in 454 grams of dinitrogen trioxide (N2O3) ?
Answer:
5.97 mol
Explanation:
To find the number of moles when given the mass of a substance, we divide the mass of the sample by its molar mass.
so, we get,
nN203 = 454 g / 76.01 g /mol
= 5.97 mol
Classify each statement as a property of ethers, alcohols, or both ethers and alcohols?
1. These compounds form hydrogen bonds between themselves and with other compounds containing an O-H, N-H, or F-H bond, such as water.
2. These compounds are water soluble if they have fewer than four carbon atoms.
3. When comparing ethers and alcohols of similar molecular weights, these compounds have the lower boiling point.
Explanation:
1. Only alcohols forms hydrogen bond between themselves and with other compounds containing an O-H, N-H, or F-H bond, such as water.
2. Alcohols up to 4 carbons are miscible in water because they have hydrogen bonded to oxygen and can form hydrogen bond with water. However, it is not possible for ethers.
3. When comparing ethers and alcohols of similar molecular weights, ethers have lower boiling point than alcohol. This is because of the presence of hydrogen bond in alcohols.
The given statements can be classified as a property of both(ether and alcohol), both(ether and alcohol), and ether, respectively.
The given property of ethers, alcohols, or both ethers and alcohols are classified as:
This statement is a property of both ethers and alcohols. Both ethers and alcohols can form hydrogen bonds due to the presence of oxygen atoms in their molecules, which can interact with other compounds containing O-H, N-H, or F-H bonds, such as water.This statement is a property of both ethers and alcohols. Both ethers and alcohols can be water-soluble if they have fewer than four carbon atoms. The presence of the oxygen atom in ethers and alcohols allows them to form hydrogen bonds with water molecules, increasing their solubility.This statement is a property of ethers. When comparing ethers and alcohols of similar molecular weights, ethers generally have lower boiling points than alcohols. This is because ethers do not have hydrogen atoms directly bonded to the oxygen atom, which reduces the strength of intermolecular hydrogen bonding compared to alcohols. As a result, ethers have weaker intermolecular forces and lower boiling points.Hence, the statements can be classified as shown above.
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what are twin primes between 1 to 100
Sandy is conducting an investigation to find out which
food his dog likes best. Which is the dependent variable
in his investigation?
color of the
dog's dish
BROWN
amount of
food eaten
the type of
food given
PINK
LIGHT GREEN
Answer: Whats the question?