Answer:
12 g of 12C to three significant figures maybe?
Explanation:
tell if correct or not im sorry fi it isnt :c
A buffer solution contains 0.345 M acetic acid and 0.377 M sodium acetate . If 0.0613 moles of potassium hydroxide are added to 250 mL of this buffer, what is the pH of the resulting solution ? (Assume that the volume does not change upon adding potassium hydroxide. )
Answer:
pH = 5.54
Explanation:
The pH of a buffer solution is given by the Henderson-Hasselbach (H-H) equation:
pH = pKa + log[tex]\frac{[CH_3COO^-]}{[CH_3COOH]}[/tex]For acetic acid, pKa = 4.75.
We calculate the original number of moles for acetic acid and acetate, using the given concentrations and volume:
CH₃COO⁻ ⇒ 0.377 M * 0.250 L = 0.0942 mol CH₃COO⁻ CH₃COOH ⇒ 0.345 M * 0.250 L = 0.0862 mol CH₃COOHThe number of CH₃COO⁻ moles will increase with the added moles of KOH while the number of CH₃COOH moles will decrease by the same amount.
Now we use the H-H equation to calculate the new pH, by using the new concentrations:
pH = 4.75 + log[tex]\frac{(0.0942+0.0613)mol/0.250L}{(0.0862-0.0613)mol/0.250L}[/tex] = 5.54The temperature is -20C. If the temperature rises by 15 oC, what is the new temperature?
Answer:k c;kz;dvk
fs;fksef ;;
Explanation:
;kk;dkf;vkd; kk
What is true about sunlight?
A.It is the source of all energy for plants and animals.
B.It is the source of most of the energy for plants and animals.
C.It is the source of very little energy for plants and animals.
D.It is the source of very little energy for plants and animals.
DONT USE UP THE POINTS I WILL REPORT YOU!
Tell me if your from connexus.
I believe your answer will be D. I say this because only some animals need sun, and only some plants need sun to grow.
The periodic table has columns that group Elements according to their
A. Name
B. Properties
C. Atomic number
D. Mass
Marking brainlist
Explanation:
atomic number.............
How many molecules are in 0.55 moles of Cu(NO3)2?
3.3 × 10²³ molecules Cu(NO₃)₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
0.55 mol Cu(NO₃)₂
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 0.55 \ mol \ Cu(NO_3)_2(\frac{6.022 \cdot 10^{23} \ molecules \ Cu(NO_3)_2}{1 \ mol \ Cu(NO_3)_2})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 3.3121 \cdot 10^{23} \ molecules \ Cu(NO_3)_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
3.3121 × 10²³ molecules Cu(NO₃)₂ ≈ 3.3 × 10²³ molecules Cu(NO₃)₂
PLEASE HELP What's the mass in grams of 0.442 moles of calcium bromide, CaBr2? The atomic
weight of Ca is 40.1 and the atomic weight of Br is 79.9.
A) 452.3 g
B) 53.04 g
C) 44.2 g
D) 88.4 g
Answer: Thus there are 88.4 g of calcium bromide.
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
Molar mass of = 40.1 (1)+ 2(79.9) = 199.9
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]
[tex]0.442=\frac{x}{199.9}[/tex]
[tex]x=88.4g[/tex]
Thus there are 88.4 g of calcium bromide.
An insecticide kills many insects, but a few survive. Because of natural selection, which of the following is most likely to happen
1- Eventually the survivors will become resistant to insecticide
2- the survivors will reproduce, and the offspring will be resistant to the insecticide
3- the survivors will reproduce, but the offspring will be killed by another application of the insecticide
4- the survivors will continue to survive for many years beyond their normal lifespan
Answer:
2
Explanation:
the ones that survived are the ones that had the favorable trait, so they'll be able to reproduce and their offsprings are likely to receive that trait as well.
What is the volume of an object with the mass of 7.9 grams in the density of 2.28g/ml.
Answer:
3.7mL is the volume of the object
Explanation:
To convert the mass of any object to volume we must use density that is defined as the ratio between mass of the object and the space that is occupying. For an object that weighs 7.9g and the density is 2.28g/mL, the volume is:
7.9g * (1mL / 2.28mL) =
3.7mL is the volume of the objectWhy is boiling water a physical change
Answer:
it is cleaning the water and heating it
Answer:
When boiling the water, the water will begin to evaporate and thats the physical change.
What consist of a solid matter?
1. Name two organisms that are competing for energy and explain HOW they compete.
Answer:
There could be a few answers for this question, but my answer would be two different plants. Maybe a bush on the ground fighting for the energy of the sun with a tall tree. Leaves collect the energy from the sun and convert it to energy usable for the plant. a bush on the ground would be fighting for the sunlight with a tall tree.
How is a molecule different
from an element?
A. An element is made of more than one
type of atom.
B. A molecule has properties different
from the elements making up the
molecule.
C. An element shares electrons and a
molecule does not.
Answer:
A
Explanation:
Molecule is a substance with two or more atoms bonded together such as the oxygen humans breathe (O2). Elements are pure substances made up of all the same atoms such as gold (Au), hydrogen (H), and oxygen (O). Elements all have the same number of protons in their nuclei and can't be broken down.
Angus, Hereford, and Holstein are common types of ___
breeds.
NEED HELP NOW
Answer:Cattle
Explanation:Cattle
The graph below shows distance over time. Which of these situations
could be represented by this graph?
Pls answer quick
Answer:
the second option
Explanation:
look at the distance where the meet up at the house and the go to school
More than half of the elements are in which state of matter at room temperature?
What happens to the atomic mass when the atomic numbers increase?
Which elements does not belong to a main group of elements?
Please help I really need help!!
Answer:gas
Explanation:
how many grams of carbon tetrachloride can be produced from reacting 709.0 grams of chlorine (CI2) with excess methane?
how is the water cycle the driving process behind weathering erosion and deposition
What is a coefficient?
Answer:
in math it's " a numerical or constant quantity placed before and multiplying the variable in an algebraic expression (e.g. 4 in 4x y)."
In physics " a multiplier or factor that measures some property."
Explanation:
hope this is helpful!
Answer:
A coefficient is the number before a variable
Explanation:
A numerical or constant quantity placed before and multiplying the variable in an algebraic expression
Make a song give me some bars
Answer:
Make me a song give me some bars wait am i rappin to hard livin life high crazy right touch on her shhh f in th mhm aint waistin no time lets get into it tonight
Explanation:
A sample of gas has a volume of 12.0L and a pressure of 2.00 atm. If the pressure of gas is increased to 6.00 atm, what is the new volume of the gas?
A. 2L
B. 4L
C. 16 L
D. 8L
Answer:
B; 4 L
Explanation:
From the Boyle’s law of gases, the volume occupied by a given mass of gas is inversely proportional to the pressure exerted by the gas
Mathematically, we have this as;
PV = K
Given;
P1 = 2 atm
V1 = 12 l
P2 = 6 atm
V2 = ?
We have that;
P1V1 = P2V2
2 * 12 = 6 * V2
V2 = (2 * 12)/6
V2 = 24/6
V2 = 4 L
C2H6 + Cl* => C2H5* + HCl
Answer:
C2H6 + Cl → C2H5 + HCl
equation is balanced
How many atoms are in 0.256 mol Fe?
For this one, you can use the formula:
# of atoms = # of moles * Avogadro's number
# of atoms = (0.256 mol) * (6.02 * 10^23)
# of atoms = 1.54 * 10^23 atoms
Hope It helped you!
Atoms are the smallest unit of molecules. In 0.256 mol of iron, there are 1.54 × 10²³ atoms.
What are atoms?Atoms are small entities of the compound or the molecule that can be measured by Avogadro's number. The number of atoms can be given as the product of the moles and the Avogadro's number.
If 1 mole of iron = 6.02 × 10²³
Then, 0.256 moles = 0.256 × 6.02 × 10²³
Therefore, 1.54 × 10²³ atoms of iron are present in 0.256 moles.
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Which part of an atom would be found orbiting the nucleus?
Answer:
electrons
Electrons are negatively charged particles that orbit the nucleus. The number of electrons depends on the element and it is an ion or not
before phase change: molecules move around each other 15. The medicine in the diagram above has molecules that are moving around each other. The doctor needs to slow down the molecules enough to cause a phase change. How will she do this, and how will this affect the medicine? I She transfers energy ... a into the medicine until it is a liquid. b) into the medicine until it is a gas. C out of the medicine until it is a solid. d out of the medicine until it is a liquid. LE 1 21 Illuminate Education, Inc.
Answer:
She transfers energy out of the medicine until it is solid. So the answer would be C.
Explanation:
According to the forces of attraction , molecules can be slowed down by moving out of the medicine until it is a solid , it will decrease the rate of absorption of medicine.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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0.24 moles of a gaseous product from a reaction is collected in a 25.0-L container at a pressure of 300.0 kPa. Determine the temperature (in °C) at which the gas was collected.
Answer:
3428.58 °C
Explanation:
We'll begin by converting 300 KPa to atm. This can be obtained as follow:
101.325 KPa = 1 atm
Therefore,
300 KPa = 300 KPa × 1 atm / 101.325 KPa
300 KPa = 2.96 atm
Next, we shall determine the temperature. This can be obtained as follow:
Number of mole (n) = 0.24 mole
Volume (V) = 25 L
Pressure (P) = 2.96 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =?
PV = nRT
2.96 × 25 = 0.24 × 0.0821 × T
74 = 0.24 × 0.0821 × T
Divide both side by 0.25 × 0.0821
T = 74 / (0.24 × 0.0821)
T = 3755.58 K
Finally, we shall convert 3755.58 K to °C. This can be obtained as followb:
T(°C) = T(K) – 273
T(K) = 3755.58 K
T(°C) = 3755.58 – 273
T(°C) = 3428.58 °C
Thus, the temperature at which the gas was collected is 3428.58 °C
1. The type of bond most likely to
occur between Mg and Br is a(n)
bond.
---
Answer:
Ionic bond.
Explanation:
Group 7 elements like Bromine (Br) and group 2 elements like Magnesium,(Mg) involved loss and gain of electrons which is typical with Ionic bonding.
What is the correct IUPAC name for Al(IO₃)₃?
Answer:
Aluminum Iodate
The IUPAC name of Al(IO3)3 is diiodyloxyalumanyl iodate.
What is IUPAC name ?The systematic method of nomenclature of the organic or inorganic compound on the basis of International Union of Pure and Applied Chemistry.
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h-h+cl+cl____2h-cl... calculate the energy needed to break the bond
Choose the options below that are true. (select all that apply) Select all that apply:
a. The rate law for a given reaction can be determined from a knowledge of the rate-determining step in that reaction's mechanism.
b. The rate laws of all chemical reactions can be determined directly from their net chemical equations.
c. The rate laws of bimolecular elementary reactions are second order overall.
d. The rate law for a given reaction can be determined from its reaction mechanism,
Answer:
a, c are true statements
Explanation:
First statement concludes that only the slower stage or the rate deciding phase of the reaction allows for the rate law to be calculated. This is true
The second declaration is not valid in all regards, because we can not evaluate the correct rate law by just observing the net equation. It needs to be determined experimentally.
In the third statement, most of the bimolecular reactions are second order in general, since two reactants exist. Hence, it is true
The fourth declaration is wrong. To measure the rate of each elemental phase accompanying the response, we must observe the rates
Dogs are derived from wolves. Today, dogs are very diverse, varying in size from very small to very large. What led to this variety
1 - selective breeding
2- cloning
3- Genetic Engineering
4- Natural Selection
Answer:
1
Explanation:
i think but yes
Dogs are derived from wolves. Dogs are very diverse, varying in size from very small to very large. The variety is because of selective breeding. Hence option 1 is correct.
What is selective breeding?Selective breeding is defined as the method by which people pick which male and female animals or plants would reproduce sexually and create offspring together in order to selectively acquire specific phenotypic features. The goal of selective breeding is to produce cattle with desirable features that are strongly heritable and can thus be passed down from generation to generation.
Despite the fact that all dogs are descended from wolves, people have significantly changed the appearance of dogs through the use of artificial selection. Dogs have been bred for various desirable traits for ages, resulting in a vast variety of canines, from the little Chihuahua to the enormous Great Dane.
Thus, dogs are derived from wolves. Dogs are very diverse, varying in size from very small to very large. The variety is because of selective breeding. Hence option 1 is correct.
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