Answer:
C. a change in the total mass of the product
Explanation:
A chemical reaction is a reaction that alters the chemical composition of the substances involved. Based on the options in this question, a chemical reaction possess the following features:
- The atoms of the substance called reactants are rearranged into products but the total number of atoms remain the same after the reaction.
- A change in odor occurs as one of the indicators that a chemical reaction has taken place.
- Energy is either absorbed (endothermic) or released (exothermic) in the chemical reaction.
However, one untrue option is that "there is a change in the total mass of the product". The total mass of a chemical reaction does not change i.e. remains the same, before or after the reaction in accordance to the law of conservation of mass.
how many grams are represented by 1.45 moles of Koh? Determine your answer to the correct number of significant figures.
Answer:
[tex]\boxed {\boxed {\sf 81.4 \ g\ KOH}}[/tex]
Explanation:
We are asked to convert 1.45 moles of potassium hydroxide (KOH) to grams.
1. Molar MassThe molar mass is the mass in grams of 1 mole of a substance. The values are found on the Periodic Table. They are the same as the atomic masses but the units are grams per mole (g/mol) instead of atomic mass units (amu).
We have the compound KOH. Look up the molar masses of the individual elements.
Potassium (K): 39.098 g/mol Oxygen (O): 15.999 g/mol Hydrogen (H): 1.008 g/molThe formula for the compound has no subscripts, so there is 1 mole of each element in 1 mole of the compound. We can simply add the molar masses.
KOH: 39.098 + 15.999 + 1.008 =56.105 g/mol2. Convert Moles to GramsBased on the molar mass, there are 56.105 grams of KOH in 1 mole. Create a ratio using this information.
[tex]\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}[/tex]
We are converting 1.45 moles of KOH to grams, so we multiply by this value.
[tex]1.45 \ mol \ KOH *\frac {56.105 \ g\ KOH}{ 1 \ mol \ KOH}[/tex]
The units of moles of KOH cancel.
[tex]1.45\ *\frac {56.105 \ g\ KOH}{ 1 }[/tex]
[tex]81.35225 \ g\ KOH[/tex]
3. RoundThe original measurement of moles has 3 significant figures, so our answer must have the same.
For the number we calculated, that is the tenths place. The 5 in the hundredths place (81.35225) tells us to round the 3 up to a 4.
[tex]81.4 \ g\ KOH[/tex]
Approximately 81.4 grams of potassium hydroxide are represented by 1.45 moles.
1.4 Which one of the following does not fit in with the rest?
A a layer of oil on water
B cream on milk
C С water on top of the syrup in a cooldrink mixture
D a plank floating on water
Answer:
D a plank floating on water
Explanation:
Its not a mixture
HELP PLEASEEEEE HURRY!!
Answer:
The answer is c
What factors generally determine whether a reaction happens or not?
A. Reaction rate and color
B. Presence of water and salt
C. Enthalpy and entropy
D. Keg and Ka
Answer:
Explanation:
The answer is C Enthaply and entropy because temperature plays a big role in reactions
Answer:
c
Explanation:
a p e x :)
En términos de energía, ¿a qué se debe que sea más difícil detener un camión en comparación a una bicicleta?
Answer:
hola
Explanation:because si
How many grams of Al will be deposited from molten AlCl3 by a current of 15.0 amp flowing for 24.0 hr ( 1 Faraday = 96500 C)
0.538 g
0.0335 g
363 g
121 g
Answer:
121 aprox.
Explanation:
mass/molar mass = Q/CF
where mass=?
molar mass of Al=27
Q=It = 15×24×60×60
C=3
F=96500
ASAAAP HURRRY PLS!!!
Where in aerobic respiration is the largest amount of energy produced?
A)
At the beginning of the cycle, when glucose is oxidized to pyruvate.
B)
At the end of the electron transport chain, when oxygen is reduced.
C)
At the end of the electron-transport chain, when oxygen is oxidized.
D)
At the beginning of the electron transport chain, when oxygen is oxidized.
The atoms of elements A (blue) and B (orange) form 2 compounds shown here. Do these compounds obey the law of multiple proportions?
Hello. You have not presented the image that presents the two elements mentioned in the question. This makes it impossible for your question to be answered. However, I will try to help you as best I can.
To say whether the compounds obey the law of multiple proportions, you should observe whether one of the elements, formed from the compounds, maintains a fixed mass, while the other element presents the mass in a varied amount of small, whole numbers, spread across the formed compounds .
This is because the law of multiple proportions states that an element must have a fixed mass when reacting with another element to create compounds. This reaction will allow this element to keep the mass fixed, while the other element will generate different compounds, where each one presents a part of the mass of the forming element, in small and whole numbers.
1. What metal is oxidized in the most common dry cell?
zinc
iron
carbon
copper
Answer:
the correct answer is zinc
What is created when electrons become detached from their local atom?'
a) An Atom
b) Cation
c) Anion
d) Delocalized electrons
Answer:
B. Cation
Explanation:
As an electron is removed from the atom it is then converted into a positively charged ion known as a Cation.
Hope this helps u
A reaction requires 22.4 L of gas at STP . There are 25.0 L of gas at 101.5 kPa and 373 K.
Which statement is true?
Use the ideal gas law: PV = nRT where R = 8.31 L-kPa/mol-K
A. There is not enough gas for the reaction.
B. Given this information, there is no way to tell if there is enough gas for the reaction.
C. There is excess gas for the reaction.
D. There is enough gas for the reaction.
Answer:
STP is 101.325 kPa pressure and 273K temperature
Also, at STP, 1 mol of an ideal gas = 22.4 L
Since the question states that 22.4 L are needed at STP, we know that ONE MOLE is needed. Now, the question is, how many moles are actually present?
V = 25.0 L
P = 101.5 kPa
T = 373K
n = ?
R = 8.31 L-kPa/Kmol
Solving the ideal gas law for n (moles) and comparing that to 1 mole, we have...
n = PV/RT = (101.5)(25.0)/(8.31)(373)
n = 0.82 moles of gas. THIS IS NOT ENOUGH as it is less than the ONE mole required.
Explanation:
Para la siguiente reacción: 2NH 3(g) + CO 2(g) ———> (NH 2 ) 2 CO (l) + H 2 O (l) a) ¿Cuántos gramos de NH 3 se necesitan para formar 720 g de (NH 2 ) 2 CO? b) ¿Cuántos moléculas de agua se obtienen a partir de 9 litros de CO 2 ayudenme porfa
Answer:
a. 408g de NH3 son necesarios
b. 2.42x10²³ moléculas de agua se obtienen
Explanation:
a. Basados en la reacción, 2 moles de NH3 producen una mol de (NH2)2CO. Para resolver esta pregunta debemos convertir la masa de (NH2)2CO a moles. Estas moles a moles de NH3 y su respectiva masa:
Moles (NH2)2CO -Masa molar: 60.06g/mol-
720g * (1mol / 60.06g) = 11.99 moles (NH2)2CO
Moles NH3:
11.99 moles (NH2)2CO * (2mol NH3 / 1mol (NH2)2CO) = 23.98 moles NH3
Masa NH3 -17.031g/mol-:
23.98 moles NH3 * (17.031g / mol) = 408g de NH3 son necesarios
b. 1mol de CO2 produce 1mol de agua. Se debe convertir el volumen a moles usando PV = nRT. Estas moles = Moles de agua. 1mol = 6.022x10²³ moléculas:
Asumiendo STP:
PV = nRT; PV / RT = n
Donde P = 1atm a STP
V = 9L
R = 0.082atmL/molK
T = 273.15K a STP
1atm*9L / 0.082atmL/molK*273.15K = n
n = 0.402 moles CO2 = Moles H2O
Moléculas:
0.402 moles agua * (6.022x10²³ moléculas / 1mol) =
2.42x10²³ moléculas de agua se obtienen. A circuit is set up with two parallel resistors, each of a resistance of 250Ω. a. What is the total resistance for this circuit?
Answer:
125 ohms
Explanation:
since they're parallel we do
1/total resistance = (1/250 ohms) + (1/250 ohms)
then you get 2/250 ohms
then you flip it so it's equal to total resistance/1
250÷2= 125
How many liters of hydrogen gas will be produced at STP from the reaction of 5.159 x 1021 atoms of magnesium with 55.23 g of phosphoric acid (H3PO4)?
3 Mg + 2 H3(PO4) Mg3(PO4)2 + 3 H2
Answer:
0.190L of hydrogen may be produced by the reaction.
Explanation:
Our reaction is:
3Mg + 2H₃PO₄ → Mg₃(PO₄)₂ + 3H₂
We need to determine the limting reactant. Let's find out the moles of each:
5.159×10²¹ atoms . 1 mol / 6.02×10²³ atoms = 0.00857 moles of Mg
55.23 g . 1 mol / 97.97 g = 0.563 moles of acid
2 moles of acid react to 3 moles of Mg
0.563 moles of acid may react to: (0.563 . 3) /2 = 0.8445 moles of Mg
Definetely the limting reactant is Mg.
As ratio is 3:3, 3 moles of Mg can produce 3 moles of hydrogen
Then, 0.00857 moles of Mg must produce 0.00857 moles of H₂
At STP, 1 mol of any gas occupies 22.4L
0.00857 mol . 22.4L / 1mol = 0.190L
The melting and boiling points of table salt and table sugar are given below.
Why does table salt have much higher melting and boiling point than table sugar?
o A strong ion -ion attractions in table salt
O B. weak ion-ion attractions in table sugar
O C. strong ion-ion attractions in table sugar
O
D. weak ion-ion attractions in table salt
Answer:
weak ion attractions in the table salt
CaC0³ scientific name is?
Answer:
CaC0³ scientific name is Calcium carbonate
Explanation:
Have a great summer :)
Jello has a density of 1.14 g/mL. A box of Jello makes 475 mL of Jello and has 13 g of sugar. Determine the % m/m of sugar in the Jello. (Hint: d=m/v)
Answer:
2.34 %
Explanation:
Since the density of the Jello, ρ = 1.14 g/mL and ρ = m/v where m = mass of jello and v = volume of jello = 475 mL.
So, m = ρv
substituting the values of the variables into the equation, we have
m = ρv
m = 1.14 g/mL × 475 mL = 541.5 g
Since we have 13 g of sugar in the jello, the total mass present is 13 g + 541.5 g = 554.5 g
So, the percentage by mass of sugar present % m/m = mass of sugar present/total mass × 100 %
= 13 g/554.5 g × 100 %
= 0.0234 × 100 %
= 2.34 %
So, the percentage by mass of sugar present % m/m = 2.34 %
Which of the following is not a compound? HCl Cl2 NaCI CO2
Answer:
CO2 it is an element.
Hope it helps:)
If you could somehow travel inside an atom and look around, what part of the atom would you want to look at? What would you want to understand better as a result of your "travels"? Write your answers in 2-3 paragraphs.
Answer:
See explanation
Explanation:
The interior of the atom is composed of electrons which move around in orbits and the nucleus. The nucleus contains protons and neutrons. The electrons are negatively charged while the protons are positively charged, the neutrons have no charge at all.
The atom is held together by electrostatic interaction between the electrons and protons in the nucleus. The protons and neutrons account for most of the mass of the atom.
The greatest wonder that I will like to really understand in the interior of the atom is the nature of the interaction between the neutrons and protons in the atomic nucleus which holds the nucleons together. The neutrons have no charge while the protons are positively charged. What sort of interaction could exist between an uncharged particle and a charged particle? That is what I will like to understand better as a result of my travels into the interior of the atom.
Answer:
help
Explanation:
Which of the following reactions would be the fastest?
A large lump of zinc with high concentration of sulfuric acid.
Small strips of zinc with high concentration of sulfuric acid.
Powdered zinc with low concentration of sulfuric acid.
Powdered zinc with high concentration of sulfuric acid.
2 DONT KNOW
Answer:
it should be powdered zinc with high concentration of sulfuric acid
is kcn a ternary ionic compound?
Answer:
The given molecule is KCN.
Is it a ternary ionic compound?
Explanation:
A ternary ionic compound is one that consists of at least one polyatomic ion/radical.
In the given molecule,
the ions present are:
K+ and CN-.
CN- is a polyatomic acidic radical.
Hence, the given molecule is ternary ionic compound.
Please somone help me with a chemistry question brainliest to whoever answers correctly and 20 points
Answer:
3132 is the answer
Explanation:
3BaCl2 + Al2S3 → 3BaS + 2AlCl3
Answer:
Explanation:
Hope this helps u !!
An electron in a hydrogen atom moves from level 1 to level 4. The electron then drops from level 4 to level 2. Which
statement describes the most likely result?
O The energy absorbed in the first move equals the energy released in the second move.
O The energy absorbed in the first move is greater than the energy released in the second move.
O The energy released in the first move equals the energy absorbed in the second move.
O The energy released in the first move is greater than the energy absorbed in the second move.
Answer:
The energy absorbed in the first move is greater than the energy released in the second move
Explanation:
Electrons require (absorb) energy to move to a higher energy level when there is a large external heat source, the presence of an electric field or by colliding with other electrons
And the amount of energy absorbed by the electron is exactly equal to the change in the energy state between the initial energy level of the electron and the destination energy level
Therefore, given that the energy level of the electron at level 2 is higher than the energy level of the electron when at level 1, we have;
The difference in the energy level between level 4 and level 1 is greater than the difference in the energy level between level 4 and level 2 and more energy is absorbed and therefore, released when the electron moves from level 1 to level 4 than when the electron drops from level 4 to level 2.
The most likely result is that 'the energy absorbed in the first move is greater than the energy released in the second move'.
Calculate the volume of this regular solid.
What is the volume of the rectangular prism?
1
6 cm
5 cm
9 cm
3
.
The volume occupied by one mole of an ideal gas at 273K and 1.01x10% Pa is 22.4 dm'mol".
What volume of hydrogen, in dm", is produced when excess magnesium ribbon reacts with 100 cm?
of 2.00 mol dm hydrochloric acid?
Mg(s) + 2HCl(aq) → MgCl, (aq) + H2(g)
A.
0.100
B.
2.24
C.
4.48
D.
22.4
Answer:D
Explanation:
Will give brainliest
What is ozone depletion in simple words
Answer:
Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created
Answer:
Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth’s surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage. The Montreal Protocol, ratified in 1987, was the first of several comprehensive international agreements enacted to halt the production and use of ozone-depleting chemicals. As a result of continued international cooperation on this issue, the ozone layer is expected to recover over time.
How does anatomy provide evidence for evolution?
I'll give brainlist!! Simple answer please.
what is quantum physics
The ideal gas law equation is: PV = nRT
Use the ideal gas law to calculate the moles of gas in a container that has a pressure
of 700kpa, volume of 2L and a temperature of 450K.
Answer:
The answer is the first option 0.37 moles
Explanation:
the ideal gas law is PV = nRT, so in the terms of n,
n = PV/RT (divide both sides by RT to let n stand alone)
given: P = 700 kpa, V = 2L, T = 450 K , R = 8.31
n = (700 * 2) / (8.31 * 450)
= 1400/3739.5
= 0.34
what is formed when oxyhaemoglobin splits
Explanation:
The haem is in turn split into iron , which forms chemical compounds as part of the blood iron pool available for future hemoglobin synthesis...
hope this help !!
