Answer:
Zero with the subscripts, +2 without them.
Explanation:
Hello!
In this case, since we consider that two silicon are bonded with four oxygen atoms to form silicon oxide according to the following chemical equation:
[tex]Si^{4+}+O^{2-}\rightarrow Si_2O_4[/tex]
It is also possible to realize it can be simplified to obtain:
[tex]SiO_2[/tex]
Which means that the total charge with the subscripts is zero, and without the subscripts +2 (+4-2).
Best regards!
what is the correct meaning of the word justify?
he was not sure how he would be able to justify. his actions to his family.
a. change for the better
b. prove to be right
c. claim to understand
d. describe in detail
3. Which compound has the greatest molar mass?
A. H2O B. C6H12O6 C. HNO3 D. C2H6
C₆H₁₂O₆ has the greatest molar mass (180 g/mol)
Further explanationGiven
Compounds of A. H2O B. C6H12O6 C. HNO3 D. C2H6
Required
The greatest molar mass
Solution
The molar mass(molecular mass-formula mass) of a compound is the sum of the relative atomic mass (Ar) of the constituent elements of the compound
A. H₂O : 2.1+16 = 18 g/mol
B. C₆H₁₂O₆ : 6.12+12.1+6.16=180 g/mol
C. HNO₃ : 1.1+1.14+3.16=63 g/mol
D. C₂H₆ : 2.12+6.1 = 30 g/mol
What is the mass of 0.5 moles of ammonia, NH3?
Answer:
Mass = 8.5 g
Explanation:
Given data:
Mass of ammonia = ?
Number of moles = 0.5 mol
Solution:
Formula:
Mass = number of moles × molar mass
Molar mass of ammonia = 17 g/mol
By putting values,
Mass = 0.5 mol × 17 g/mol
Mass = 8.5 g
I’ll mark brainliest!!!
What are the products of a fission reaction? Check all that apply.
-lighter atoms
-energy
-heavier atoms
-neutrons
-protons
Answer: lighter atoms
energy
neutrons
Explanation:
A nuclear fission is simply defined as a nuclear reaction whereby the nucleus of an atom is being divided into smaller nuclei which are also lighter. An energy is also released when this occurs.
Therefore, the products of a fission include lighter atoms, energy and neutrons.
Answer:
lighter atoms
energy
neutrons
Explanation: took test
Chrysocolla is a copper mineral that contains .016 % silicon. What is the mass of silicon present in 1.5kg of this mineral
Answer:
.24 mg
Explanation:
The mineral contains .016 % silicon
mass of the mineral = 1.5 kg
mass of silicon = 1.5 x .016 %
= 1.5 x .016 / 100
= 24 x 10⁻⁵ kg
= 24 x 10⁻² mg
= .24 mg .
Please help me thanks so much....I’ll mark you?!?!:)))) (15 points)
Answer:
a penny that has turned green
Explanation:
a chemical change is when a substance combines with another to form a new substance. the other answer choices doesn't form a new substance.
An alcohol is 62.04 % C and 10.43 % H by mass. The rest is oxygen. What is the empirical formula of the alcohol
Answer: The empirical formula is [tex]C_3H_6O[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams. So, the mass of each element is equal to the percentage given.
Mass of C = 62.04 g
Mass of H = 10.43
Mass of O = (100-(62.04+10.43)) g = 27.53 g
Step 1 : convert given masses into moles.
Moles of C = [tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{62.04g}{12g/mole}=5.17[/tex]moles
Moles of H =[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{10.43g}{1g/mole}=10.43moles[/tex]
Moles of O = [tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{27.53g}{16g/mole}=1.72moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = [tex]\frac{5.17}{1.72}=3[/tex]
For H = [tex]\frac{10.43}{1.72}=6[/tex]
For O =[tex]\frac{1.72}{1.72}=1[/tex]
The ratio of C :H : O= 3: 6 : 1
Hence the empirical formula is [tex]C_3H_6O[/tex]
An aqueous solution of 6.70 M ammonia, NH3, has a density of 0.950 g/mL. The percent by mass of NH3 in the solution is %.
Answer:
12.01% by mass
Explanation:
Percent by mass is 100 times the mass of solute (ammonia) over the mass of the solution. In molarity, we have the moles of ammonia per liter of solution. There are 6.70moles of NH3 in 1L. Thus, we need to convert the moles of ammonia to grams and the liters of solution to grams:
Mass ammonia - Molar mass: 17.031g/mol-
6.70moles * (17.031g / mol) = 114.1g NH₃
Mass solution:
1L * (1000mL / 1L) = 1000mL * (0.950g/mL) = 950g
Percent by mass:
114.1g NH₃ / 950g * 100 =
12.01% by massTiCl4+H2O-->TiO2+HCl I need to balance this
Answer: The answer is TiCl4 + 2H2O --> TiO2 + 4HCl
Explanation: Every element is equal on both sides.
Ti- 1 Ti-1
Cl- 4 Cl-4
H- 4 H-4
O- 2 O-2
1 If 5.80 L of gas is collected at a pressure of 92.0 kPa, what volume will the same gas occupy at 101.3 kPa if the temperature stays constant
Answer:
The volume that the same gas will occupy at 101.3 kPa if the temperature is kept constant is 5.27 L.
Explanation:
As the volume increases, the particles (atoms or molecules) of the gas take longer to reach the walls of the container and therefore collide with them less times per unit of time. This means that the pressure will be lower because it represents the frequency of collisions of the gas against the walls. In this way pressure and volume are related, determining Boyle's law that says:
"The volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure"
Boyle's law is expressed mathematically as:
P * V = k
Now it is possible to assume that you have a certain volume of gas V1 that is at a pressure P1 at the beginning of the experiment. If you vary the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1 * V1 = P2 * V2
In this case, you have:
P1= 92 kPaV1= 5.80 LP2= 101.3 kPaV2= ?Replacing:
92 kPa* 5.80 L= 101.3 kPa* V2
and solving, you get:
[tex]V2=\frac{92 kPa* 5.80 L}{101.3 kPa}[/tex]
V2= 5.27 L
The volume that the same gas will occupy at 101.3 kPa if the temperature is kept constant is 5.27 L.
When an alkene is subjected to treatment with Hg(OAc)2 in alcohol followed by reaction with NaBH4, what new class of compound is formed
Answer:
The new class of compound formed is an alcohol.
Explanation:
The treatment of an alkene with Hg(OAc)₂ in alcohol followed by reaction with NaBH₄ gives an alcohol. This reaction is known as oxymercuration-demercuration reaction. It is a two-step pathway which proceeds in the Markovnikov manner. In this reaction, the alkene react with the Mercury salt (Hg(OAc)₂) and a nucleophile (alcohol) to form an organomercury intermediate. The intermediate's carbon-mercury bond is then converted to carbon-hydrogen bond by the reaction with NaBH₄. An alcohol is then produced.
which of the following is NOT a clue that a chemical reaction has taken place?
A:release of gas
B:color change
C:mixing of the reactants
D:formation of a precipitate
Answer:
A
Explanation:
My reason is color change is an example
Mixing reactants is a chemical change clue
formation of precipitate is a clue
so that leaves A
Many reactions double their rates with every ten degrees rise in temperature. Assume that such a reaction takes place at 301 K and 311 K. What must its activation energy be for this statement to hold
Answer:
57.6 KJ/mol
Explanation:
We have that;
T1 = 301 K
T2= 311 K
k1 = k1
k2= 2k1
R = 8.314 JK-1
Ea= ?
So;
ln(k1/k2) = (-Ea/R) (1/T1 - 1/T2)
ln (k1/2k1) = -(Ea/8.314) (1/301 - 1/311)
ln(1/2) = -(Ea/8.314) (3.3 * 10^-3 - 3.2 * 10^-3)
-0.693 = -(Ea/8.314) 0.1 * 10^-3
-0.693/ 0.1 * 10^-3 = -(Ea/8.314)
-6930 = -(Ea/8.314)
Ea = 6930 * 8.314
Ea = 57.6 KJ/mol
A species of butterfly lives in a warm climate. The butterflies feed on the nectar of tropical flowers. Birds eat the butterflies, and they prefer to eat the butterflies with brighter wings.
20 points
What would most likely cause this species to become extinct?
a mutation resulting in darker wings
a decrease in the birds that eat the butterflies
the destruction of the butterflies’ environment
overproduction of butterfly offspring
Answer: the destruction of the butterflies’ environment
Explanation:
A mutation that would result in darker wings will mean that the birds that prey on them will stop eating a lot of them so this won't lead to extinction.
A decrease in the birds that eat the butterflies will also mean that the butterflies will survive more because they will have less predators.
Overproduction of butterfly offspring means more butterflies so they will not go extinct.
If their habitat was destroyed however, the butterflies might find it hard to survive as any new environment they go to might not be suitable leading to their extinction.
Answer:
I believe it is c
Explanation:
Observe the sodium and chlorine atoms. Assuming that the inner rings are full of electrons, how many electrons are there total in each atom
Answer:
See explanation
Explanation:
Chlorine has three shells. We know that the first shell contains two electrons, the other shell has eight electrons while the last shell has seven electrons. This means that chlorine has seventeen electrons.
For sodium, there are also three shells. The first shell has two electrons as usual. The next shell has eight electrons while the last shell has only one electron. This makes a total of eleven electrons for sodium.
Answer: sodium-11
chlorine-17
Explanation: meow
A chemist dissolves 240mg of pure barium hydroxide in enough water to make up of solution. Calculate the pH of the solution. (The temperature of the solution is .)
Answer:
pH = 12.22
Explanation:
... To make up 170mL of solution... The temperature is 25°C...
The dissolution of Barium Hydroxide, Ba(OH)₂ occurs as follows:
Ba(OH)₂ ⇄ Ba²⁺(aq) + 2OH⁻(aq)
Where 1 mole of barium hydroxide produce 2 moles of hydroxide ion.
To solve this question we need to convert mass of the hydroxide to moles with its molar mass. Twice these moles are moles of hydroxide ion (Based on the chemical equation). With moles of OH⁻ and the volume we can find [OH⁻] and [H⁺] using Kw. As pH = -log[H⁺], we can solve this problem:
Moles Ba(OH)₂ molar mass: 171.34g/mol
0.240g * (1mol / 171.34g) = 1.4x10⁻³ moles * 2 =
2.80x10⁻³ moles of OH⁻
Molarity [OH⁻] and [H⁺]
2.80x10⁻³ moles of OH⁻ / 0.170L = 0.01648M
As Kw at 25°C is 1x10⁻¹⁴:
Kw = 1x10⁻¹⁴ = [OH⁻] [H⁺]
[H⁺] = Kw / [OH⁻] = 1x10⁻¹⁴/0.01648M = 6.068x10⁻¹³M
pH:
pH = -log [H⁺]
pH = -log [6.068x10⁻¹³M]
pH = 12.227. Which of the following is not a characteristic of a solution?
a. It is a uniform mixture
b. It will scatter a beam of light
c. The solute and solvent cannot be distinguished by the naked eye
d. The solute particles cannot be separated by filtering
what is a benefit of the artificial selection for the environment and explain it. please help!!
1x+cb=23
thios is right because math
A piece of silver metal weighting 194.3 g is placed in a graduated cylinder containg 242.0 ml of water.the volume of water now reads 260.5 ml. calculate the denstyof the metal
Answer:
10.50 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
volume = final volume of water - initial volume of water
volume = 260.5 - 242 = 18.5 mL
We have
[tex]density = \frac{194.3}{18.5} \\ = 10.5027[/tex]
We have the final answer as
10.50 g/mLHope this helps you
What is the most effective long-term solution to reduce the amount of carbon dioxide emissions
Drive less
Find alternatives to fossil fuels
Increase gas mileage on cars
Recycle the gas
Answer:
Find alternatives to fossil fuels
Explanation:
The most effective long - term solution to reduce the amount of carbon dioxide emission is to find alternatives to fossil fuels.
Fossil fuels consumption and use in most industrial processes are some of the leading causes of huge carbon signatures in the atmosphere.
When fossil fuels are broken down, they release carbon dioxide into the atmosphere. Fossil fuels have become the main stay energy sources in the world today. An alternative to them will serve the ecosystem well.An isotope has 15 protons, 16 neutrons, and 15 electrons. What is the isotopic notation of the isotope
Answer:
[tex]^{31}_{15}P[/tex] is the isotopic notation of the atom
Explanation:
The isotope notation is:
[tex]^a_bX[/tex]
Where a is the mass number = Number of protons + Number of neutrons
b is atomic number = Number of protons
The atomic number define the nature of the atom, the element with atomic number = 15 is phosphorus, P:
[tex]^a_bP[/tex]
a = 15 protons + 16 neutrons = 31
b = 15
[tex]^{31}_{15}P[/tex] is the isotopic notation of the atom.
When warm air is forced upward along a cold front what might happen?
Answer: With the cold front, warm air is rapidly forced upward (like the shavings) in advance of the actual front (the “cutter”), creating towering cumulus clouds, some hard showers and quite possibly a few gusty thunderstorms followed by a push of cooler and drier air in its wake.
Explanation:
Propane is often used in stoves and cooktops as a source of heat. The combustion of propane yields water and carbon
unbalanced chemical reaction is represented by the ball-and-stick diagrama shown.
How many molecules of carbon dioxide and water are produced during the combustion of propane? Move numbers to
the equation and show that mass is conserved.
+
+
Propane molecule
Oxygen molecules
Carbon dioxide molecule
Water molecule
Legend
Hydrogen
atom
Oxygen
atom
Carbon
atom
2
3
Answer: 3 molecules of carbon dioxide and 4 molecules of water are produced during the combustion of propane.
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical reaction for combustion of propane is:
[tex]C_3H_8+5O_2\rightarrow 3CO_2+4H_2O[/tex]
3 molecules of carbon dioxide and 4 molecules of water are produced during the combustion of propane.
Circle the letter of cach sentence that is true about silica.
a. It is formed from oxygen and nitrogen. b. It makes magma thicker, .
C. It is rarcly found in the crust,
d. It produces light-colored lava.
Answer:
The correct answer choices are B and D.
Explanation:
A volcanic eruption happens when magma reaches the surface of the earth. Depending on the amount of gas and the silica content of the magma, the lava and the type of eruption can vary. Silica, which forms from the elements silicon and oxygen, makes the lava thicker and less runny. When lava is thick, the volcanic eruption tends to be more explosive. The amount of silica also changes the color and density of the lava, which then makes different kinds of igneous rocks. As the gas content of the lava goes up, the eruption becomes more explosive.
Please help me thanks so much....I’ll mark you?!?!:)))) ( 15 points)
Answer:
the first one
Explanation:
Which causes genetic variations and can result in different alleles?
predation rate
random mutations
competition
environmental changes
Answer:
Environmental Changes
Explanation:
Answer:
d
Explanation:
From the chair conformation, rotate about the carbon-carbon bonds of the ring to form a boat conformation. In the boat conformation carbon atoms 1 and 4 are both above (they could also both be below) the plane described by carbon atoms 2, 3, 5 and 6. Look through each of the C-C bonds in the cyclohexane ring. Do you observe any eclipsing interactions?
Please help me thanks so much....I’ll mark you?!?!:))))(11 points)
Answer:
the first one
Explanation:
okay this is not school related but how do you not fall for some one so hard .
Answer:
Love is not only the thing in this world!
Study hard, you can choose a better way of life.
______ is a state function dealing with the disorder of the universe, and therefore the likelihood that a chemical reaction will take place. g
Answer: Entropy.
Explanation:
If we recall the laws of thermodynamics, there is a state function called entropy, that is related to the disorder in the system.
Such that, for example, in a gas expansion, we will have an increase in the "disorder" then we will have an increase in the entropy, this happens because we have more volume where the particles can be, then we have a larger number of "microstates" (or microscopic states, which refers to the states of the particles that conform the gas)
Particularly, when we go into statistical thermodynamics, there is something called the "Statistical entropy" that is related to the information theory, where the entropy depends on the number of possible outcomes that some event, like a chemical reaction, can have.
For a larger number of possible outcomes, we will have a larger entropy (we can think of this larger number of possible options as a disorder) and this entropy will be related to the statistical probability of each one of those outcomes.
Where the (most general) equation for the entropy is:
S = Kb*Σpₙ*ln(pₙ)
Where pₙ is the probability for the n-th outcome.
Kb is Boltzman's constant.