Answer:
The answer is: true
Explanation:
In redox reactions, the half-reactions of oxidation and reduction always occur simultaneously in pair.
The oxidation half-reaction involved the lost of electrons from a reduced substance (A) to form a oxidized substance (A⁺):
A ⇒ A⁺ + e-
In contrapossition, during the reduction half-reaction the oxidized substance (B⁺) gains electrons to form the reduced subtance (B):
B⁺ + e- ⇒ B
The overall redox reaction is obtained by the addition of the two half-reactions:
A ⇒ A⁺ + e-
B⁺ + e- ⇒ B
-----------------
A + B⁺⇒ A⁺ + B
The electrons gained by B are provided by A, which lost the same number of electrons. Thus, the oxidation/reduction reactions are paired.
A chemist prepares a solution of magnesium fluoride MgF2 by measuring out 0.0113μmol of magnesium fluoride into a 450.mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in /mmolL of the chemist's magnesium fluoride solution. Round your answer to 3 significant digits.
Answer:
2.51x10⁻⁵ mmol MgF2/L
Explanation:
To find the concentration in mmol / L we need to convert μmol to mmol (1000μmol / 1mmol) and mL to Liters (1000mL / 1L) as follows:
μmol MgF2:
0.0113μmol MgF2 * (1mmol / 1000μmol) = 1.13x10⁻⁵ mmol MgF2
Liters solution:
450mL * (1L / 1000mL) = 0.450L
Concentration in mmol/L:
1.13x10⁻⁵ mmol MgF2 / 0.450L =
2.51x10⁻⁵ mmol MgF2/LHow many molecules are in Na2CrO4
Answer:
It is 161.97324 g/mol
1 molecule
During winter, you can sometimes ice skate outdoors on a frozen lake. Why can’t you ice skate on a lake when it is not frozen?
Answer:
Generally the ice should be more than 4 inches thick to skate on it safely. However, the ice thickness is not always even and there can be thin spots, especially near springs or near river inlets or outlets. Most lakes and ponds don't completely freeze because the ice (and eventually snow) on the surface acts to insulate the water below. Our winters aren't long or cold enough to completely freeze most local water bodies. This process of lakes turning over is critically important to the life in the lake.
Explanation:
help, Look at the model below. Explain what is correct and/or incorrect about the model based on scale, proportion, and quantity.
6 List What are two advantages and two
limitations of physical models?
Plz help
Answer:
Physical models can represent objects or systems that are too small, too big, or too far away to study. They are way easier, cheaper, and safer to work with or use when compared to the real objects that they represent.
Explanation:
What is the solubility in moles/liter for calcium phosphate at 25°C given a Ksp value of 1.2 x 10^-29. Write using scientific notation and use 1 or 2 decimal places.
Answer:
Explanation:
Ca₃( PO₄)₂ = 3 Ca⁺² + 2 PO₄⁻³
x 3x 2 x
Let solubility be x mole per litre
solubility product = (3x )³ x ( 2x )²
= 108 x⁵ = 1.2 x 10⁻²⁹
x⁵ = .0111 x 10⁻²⁹ = .111 x 10⁻³⁰
x = .64 x 10⁻⁶ moles / litre
Will the boiling point of water be higher or lower in the maintains, where the altitude is high, and the pressure is low ?
What is the name of the groups that contain Iron(Fe) and Gold(Au)?
Answer:
Transition Metals
Explanation:
Answer:
Group 8 & 11
Explanation:
Transition Metals
Which shows three human body parts in order from the simplest level of organization to the most complex?
red blood cell → nervous system → bone tissue
nervous system → bone tissue → red blood cell
red blood cell → heart tissue → circulatory system
bone tissue → red blood cell → nervous system
Answer:
red blood cell → heart tissue → circulatory system
Explanation:
The levels of organization from the simplest level of organization to the most complex is cell, tissue, organ, organ, organ system, and organism. Red blood cells are cells, heart tissue is tissue in the heart and the circulatory system is an organ system that ensures blood, oxygen, and nutrients are flowing through the body.
Red blood cell → heart tissue → circulatory system shows the three human body parts in order from the simplest level of organization to the most complex.
What is heart?Heart is a muscular organ which is present in most of the animals , it is responsible for pumping blood via the blood vessels to the entire body.The blood which is pumped carries oxygen and nutrients along with it.Along with it on it's way back to heart it carries carbon dioxide to the lungs.
Heart has an approximate size of a closed fist and is present between the lungs in the middle compartment of the chest. It is divided in to for chambers , the upper chambers called atria and lower ones called ventricles.
The wall of the heart is made up of three layers : epicardium,myocardium and endocardium. It pumps blood with a rhythm which is determined by a group of cells which are called the pacemaker cells present in the sinoatrial node.
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How would I find the answer?
Answer:
Kr
Explanation:
The noble gas that is isoelectronic with Br⁻ is krypton.
This is because krypton is the closest noble gas to Br on the periodic table.
Electronic configuration of Bromine is;
2, 8, 18, 7
Br⁻ becomes; 2, 8, 18, 8
Krypton is; 2, 8, 18, 8
___ is a type of weathering caused by a chemical reaction with water.
A. Carbonation
B. Abrasion
C. Hydrolysis
D. Hydration
Option ( C ). Hydrolysis (/haɪˈdrɒlɪsɪs/; ancient Greek for "water" and "to dissolve") is a chemical reaction in which water molecules break one or more chemical bonds.)
What does the example of hydrolysis mean?
Hydrolysis is the process of breaking down compounds by adding water. Here is an example of hydrolysis:
Sodium acetate is a type of salt. When sodium acetate is mixed with water, the chemical bonds are broken and it breaks down into sodium ions and acetate ions.
What is function of hydrolysis?
Hydrolysis reactions break the bonds and release energy. Biopolymers are ingested and hydrolyzed in the gastrointestinal tract to form small molecules that can be absorbed by cells and further broken down to release energy.
Where does the hydrolysis take place?
Hydrolysis is the process by which compounds are broken down into simpler compounds and involves the chemical uptake of water. Almost all tissues contain enzymes that catalyze hydrolysis, but the highest concentration is in the liver.
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In a closed system, the total energy before an energy transformation is _______ the total energy after it.
A.
less than
B.
equal to
C.
unrelated to
D.
greater than
In a closed system, the total energy before an energy transformation is greater than the total energy after it.
What is a closed system ?A closed system is a natural physical system that does not permit the movement of matter into or out of the system, while energy transfer is permitted in some situations, such as those found in physics, chemistry, or engineering.
A closed system is one that only allows the flow of energy; it forbids the exchange of matter. The heat can transfer when we boil water with a closed cover, but the matter cannot.
In a closed system, the overall energy is constant. The universe's overall energy is always changing. Mass may be used to store energy. In a closed system, energy may be transformed from one form to another.
Thus, option D is correct.
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Compare and contrast the applications and benefits of circle graphs and bar charts. Explain
Answer:
A circle graph, or a pie chart, is used to visualize information and data. A circle graph is usually used to easily show the results of an investigation in a proportional manner. Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.
Explanation:
In short, bar graphs are better to keep track of data over long periods of time, and circle graphs are better when you are trying to visualize a specific set of data.
Circle graph can be also be called pie chart, which is more widely used. It is usually made up of a circle, divided into parts or pies. In the divided parts, it is used to differentiate between different data.
Bar charts on the other hand are like graphs having both x and y axis. It is used to represent data with respect to the height of the graph. Each data is divided into different smaller parts on the graph.
Example of what they look like is attached below.
First one is bar chart while the second is a circle graph
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Are light and other forms of energy are made of atoms
Answer:
yes they are
Explanation:
Aluminum has a density of 2.70 g/mL. Calculate the mass (in grams) of a piece of aluminum having a volume of 238 mL .
Answer:
mass in gram = 642.6 g
Explanation:
Given data:
Density of aluminum = 2.70 g/mL
Volume of aluminum = 238 mL
Mass in gram = ?
Solution:
Density:
Density is equal to the mass of substance divided by its volume. The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
d =m/v
d = density
m=mass
V=volume
Now we will put the values in formula.
2.70 g/mL = m/ 238 mL
m = 2.70 g/mL × 238 mL
m = 642.6 g
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of carbon tetrachloride would be produced by this reaction if of chlorine were consumed
Answer:
0.56 mL
Explanation:
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of carbon tetrachloride would be produced by this reaction if 1.1 mL of chlorine were consumed.
Step 1: Write the balanced equation
CH₄(g) + 2 Cl₂(g) → CCl₄(g) + 4 HCl (g)
Step 2: Calculate the moles corresponding to 1.1 mL of Cl₂
At standard temperature and pressure, 1 mole of a gas has a volume of 22.4 L.
1.1 × 10⁻³ L × 1 mol/22.4 L = 4.9 × 10⁻⁵ mol
Step 3: Calculate the moles of CCl₄ formed from 4.9 × 10⁻⁵ moles of Cl₂
The molar ratio of Cl₂ to CCl₄ is 2:1. The moles of CCl₄ are 1/2 × 4.9 × 10⁻⁵ mol = 2.5 × 10⁻⁵ mol.
Step 4: Calculate the volume corresponding to 2.5 × 10⁻⁵ moles of CCl₄
At standard temperature and pressure, 1 mole of a gas has a volume of 22.4 L.
2.5 × 10⁻⁵ mol × 22.4 L/mol = 5.6 × 10⁻⁴ L = 0.56 mL
The noble gases can be found in group/period ____
Answer:
group 18
Explanation:
The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive
Answer:group 18
Explanation
Which of the following statement best defines matter?
Is NH4CIO3 ionic or ionic using the stock system or molecular
Answer:
I believe it would be ionic using the stock system.
Explanation:
The only difference is the size of cations, Cs+ being larger than Na+ and hence Na+ will have more polarising power than Cs+ and hence NaCl will be more covalent than CsCl or in other words CsCl will be more ionic than NaCl.
In general, atoms that have a high electronegativity have a ____ first ionization energy and a ____ atomic radius.
NEED ASAP
Select one:
a. low, small
b. high, large
c. low, large
d. high, small
Answer:
The correct option is D
Explanation:
Firstly, let's define the periodicity of these terms and then draw conclusion from there.
Ionization energy is the amount of energy required to remove an electron from a gaseous atom in it's ground state. This property increases across a group in the periodic table.
Electronegativity is the measure of the property/tendency of an atom to attract an electron. This property also increases across a period. Thus, elements that have high electronegativity also have a high ionization energy.
Atomic radius is however the distance between the central nucleus to the outermost electron. This property decreases across the period. Thus, as electronegativity and ionization energy increases, atomic radius decreases.
From the above, it can be deduced that the correct option is d
Answer:high,small
Explanation:
I have the same test and I got it right
describe the dual nature of electrons (give an example)
Answer:
In 1924, the French physicist, Louis de Broglie suggested that if light has electron, behaves both as a material particle and as a wave. According to this theory, small particles like electrons when in motion possess wave properties.
Explanation:
examples
This can be derived as follows according to Planck’s equation, E = hv = hc /λ ∴ v=c/λ(energy of the photon (on the basis of Einstein’s mass energy relationship) E = mc2
( If Bohr’s theory is associated with de-Broglie’s equation then wave length of an electron can be determined in bohr’s orbit and relate it with circumference and multiply with a whole number 2πr = nλ or λ = (2πr/2π) From de-Broglie equation, λ = (h/mv).
If a neutral atom has 49 protons, how many electrons does it have?
Which of the following statement best defines matter?
Answer:matter is anything has mass and take up space
Explanation:
What is the chemical name of the compound NH4SCN?
Its called "Ammonium thiocyanate" Have a great day!! <3
Answer:
it is called Ammonium Thiocyanate or Thiourea
Explanation:
it is made made up of 2 nitrogen atoms, 4 hydrogen atoms, 1 sulfur atom and 1 carbon atom. stay safe and have a great day! TPWK
If you travel 7.5 km and walk for 1.5 h, what is your average speed?
Show your work?
Liquid nitrogen is kept at a temperature of -320 degrees. When liquid nitrogen is heated it quickly boils and turns into a gas. Which pair of pictures represent the change caused by adding heat to liquid nitrogen?
So when something is boiling it is moving faster meaning the molecules are more spread out and not condense like a solid
So the answer is the 2nd set
Balance the reaction below using the correct coefficient.
__Ag2S --> __Ag + __S8
Answer:
8Ag2S--->16Ag+S8
Explanation:
thats your answer hope it helps
8. ______________ and _____________ are located in the nucleus.
Answer:
protons and neutrons are located in the nucleus.
Iron, an element with the chemical symbol Fe, is an important element. It is used to make steel and is part of the substance that transports oxygen throughout the human body.
Which statement about Fe is supported by the modern atomic theory but not John Dalton’s theory?
A. The element iron is composed of small particles called atoms.
B. The electrons of iron have probable locations in a region of space around the nucleus.
C. Iron atoms combine with other atoms in whole number ratios to form compounds.
D. Chemical reactions that involve iron do not create new atoms of iron.
Answer:
i think its B
Explanation:
Answer:
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Explanation:
If a reaction generated 3.5 g of H2O how many moles of water were formed?
Answer:
0.19 mol H₂O
General Formulas and Concepts:
Chem
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
Given: 3.5 g H₂O from RxN
Step 2: Define conversions
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Step 3: Convert
[tex]3.5 \ g \ H_2O(\frac{1 \ mol \ H_2O}{18.02 \ g \ H_2O} )[/tex] = 0.194229 mol H₂O
Step 4: Check
We are given 2 sig figs. Follow sig fig rules.
0.194229 mol H₂O ≈ 0.19 mol H₂O