Answer:
a+c=272
27a+24c=7,137
Explanation: Hope this helps!!!
a sample of helium gas is in a sealed rigid container
is there a question or no? im confused.
Which statement describes a physical change? *
A. An iron bolt on a bridge rusts and weakens the bridge.
B. The surface of a silver cup turns black when it is exposed to air.
C. A sculptor casts a statue in molten bronze and allows it to harden.
D. Slivers of magnesium in fireworks form a bright glow as they burn.
The statement that describes a physical change is a sculptor casts a statue in molten bronze and allows it to harden. The correct option is C.
What are physical changes?"A physical change is one that simply affects the physical nature of the substance." Usually, increasing the temperature or applying pressure, both, will cause a physical change. In other words, physical changes are reversible.
All the other options like rusting of iron bolts on a bridge is a chemical change when iron reacts with oxygen in the air, it gets rust.
Similarly, silver cups exposed to air react with air is a chemical change, and option d, silver off magnesium that creates light, is also a chemical change.
Thus, the correct option is C. A sculptor casts a statue in molten bronze and allows it to harden.
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How many grams of oxygen, O2 are produced if 52.0g of potassium chlorate, KClO3, decomposes? (The molar mass of O2 = 32 g/mol and the molar mass of KClO3 = 122.4 g/mol).
Answer:
20.39 g of O2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2KClO3 —> 2KCl + 3O2
Next, we shall determine the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation. This is illustrated below:
Molar mass of KClO3 = 122.4 g/mol
Mass of KClO3 from the balanced equation = 2 × 122.4 = 244.8 g
Molar mass of O2 = 32 g/mol
Mass of O2 from the balanced equation = 3 × 32 = 96 g
Summary:
From the balanced equation above,
244.8 g of KClO3 decomposed to produce 96 g of O2.
Finally, we shall determine the mass of O2 produced from the decomposition of 52 g of KClO3. This can be obtained as follow:
From the balanced equation above,
244.8 g of KClO3 decomposed to produce 96 g of O2.
Therefore, 52 g of KClO3 will decompose to produce =
(52 × 96)/244.8 = 20.39 g of O2.
Thus, 20.39 g of O2 is produced.
A solution of EDTA is prepared by dissolving 1.986 grams of solid in approximately 500 mL of water. A standard calcium ion solution is then prepared by dissolving 0.2191 grams of chelometric calcium carbonate in HCl until dissolved, evaporating off the solvent, then redissolving into a 250.0 mL volumetric flask. A 25.00 mL aliquot of this calcium solution required exactly 26.18 mL of the EDTA solution to reach an Eriochrome Balck T endpoint. What is the concentration of the EDTA solution
Answer:
0.02088M of EDTA
Explanation:
The Ca²⁺ is chelated in presence of EDTA in a relation 1:1, when there is no free Ca²⁺ the eriochorme black T change its colour showing endpoint.
Thus, we need to find final concentration of Ca²⁺ solution and, thus, we can find concentration of the EDTA solution:
Molarity Ca²⁺ solution:
0.2191g * (1mol / 40.08g) = 0.005467 moles of Ca²⁺ in 250mL = 0.250L:
0.005467 moles of Ca²⁺ / 0.250L = 0.02187M
Moles of Ca²⁺ added:
0.025L * (0.02187 mol / L) = 5.467x10⁻⁴ moles of Ca²⁺ = Moles of EDTA at endpoint.
Molarity EDTA:
5.467x10⁻⁴ moles EDTA / 0.02618L = 0.02088M of EDTA
calculate the equivalent weight of acid on the basis of given reaction. NaoH + H2So4 gives NaHSo4 + H20.
Answer:
98
Explanation:
Based on the reaction:
NaOH + H2SO4 → NaHSO4 + H2O
Where 1 mole of the base (NaOH) reacts per mole of the acid (H2SO4)
The formula of equivalent weight is:
Equivalent weight = Molecular mass / Number of equivalent moles
Where Molecular mass of sulfuric acid is 98g/mol
And number of equivalent moles = 1 -Because 1 mole of acid reacts per mole of base
Equivalent weight is:
98 / 1 =
98
PLEASEEE HELP ?!?!?!
which of the following processes provide evidence of the particulate nature of matter
I. Diffusion
II. Filtration
III. Osmosis
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Answer:
B
Explanation:
I think the answer is Diffusion and Osmosis
The processes that provide evidence of the particulate nature of matter would be diffusion and osmosis.
Matter is defined as anything with mass/weight and able to occupy space. Matters could be molecules of solid, liquid, or gases. The molecules of each category of matter have their specific characteristics.Molecules of liquids and gases are able to diffuse. Diffusion is defined as the movement of molecules from the region of high concentration to the region of low concentration. Molecules of solids in the dissolved form are also able to diffuse. Water molecules are also able to move from the region of high to the region of low water potentials by osmosis in the presence of a semi-permeable membrane.Thus, both diffusion and osmosis back up the particulate nature of matter.
More on the particulate nature of matter can be found here: https://brainly.com/question/15230454?referrer=searchResults
Identify the double displacement reaction
2NH3+H2SO4
Answer:
......................
nh42so4
If 33.9g NaCl are mixed into water and the total mass is 578g, what is the CHANGE in freezing if Kb= - 1.82C/M (molal)? Assume NaCl does not dissociate in solution.
Answer:
-1.82 °C
Explanation:
Step 1: Given data
Mass of NaCl (solute): 33.9 gMass of water (solvent): 578 g = 0.578 kgFreezing point depression constant for water (Kb): -1.82 °C/mStep 2: Calculate the molality of the solution
We will use the following expression.
m = mass of solute / molar mass of solute × kg of solvent
m = 33.9 g / 58.44 g/mol × 0.578 kg
m = 1.00 m
Step 3: Calculate the freezing point depression (ΔT)
The freezing point depression is a colligative property that, for a non-dissociated solute, can be calculated using the following expression:
ΔT = Kb × m
ΔT = -1.82 °C/m × 1.00 m
ΔT = -1.82 °C
Which is the noble gas configuration for 31 Ga?
Answer:
1s22s22p63s23p63d104s24p1.
Explanation:
Gallium, Ga has 31 protons and 31 electrons.
Answer:
Ar 3d10 4s2 4p1
Explanation:
hope this serves you well!!
If I Gave A Pig Bacon Would He Eat It ?
Experiment: Turn on Show electronegativity. Electronegativity (EN) describes how strongly an atom attracts a pair of shared electrons. The higher the EN value, the greater the tendency of an atom to hold onto electrons in a bond and become negatively charged. Electronegativity difference is found by subtracting the EN value of one atom from another. Choose two nonmetals with a small (or no) EN difference between them. Click Play. What happens to the shared electrons in this bond
Answer:
See explanation
Explanation:
If we take two nonmetals with little or no electronegativity difference between them, the shared electrons are not attracted greatly towards any of the bonding atoms. In other words, the shared electrons remain equidistant between the nuclei of the two bonding atoms.
The bond is nonpolar since polarity is introduced into covalent bonds by a significant difference in electronegativity of the bonding atoms.
Ramps make work easier by decreasing the amount of force needed to move an object by ______ the distance it travels.
A. reducing
B. increasing
C. equalizing
What would have a higher boiling point water or hydrocarbon ( from penny liquid stacking)
Answer:
Im pretty sure its hydrocarbon
Explanation:
What temperature units
should be used when
performing calculations using
Charles's Law?
Answer:
Kelvin (K) onlyExplanation:
Kelvin is preferred for solving problems related to Charles' Law because , it is the Absolute temperature scale.
To convert Celsius to Kelvin scale, you add 273 to the temperature in the centigrade/Celsius scale.
HELP ASAP DUE IN 5 MINUTES WILL GIVE BRAINLIEST
Energy is conserved within a system, meaning that forms of energy are either transferred or transformed as they interact with objects. Which of the statements below correctly describe how energy is transferred or transformed in daily life?
Group of answer choices
Kinetic energy transforms into thermal energy when a heating pad is turned on.
Electrical energy is transferred into light energy so that a flashlight generates light when it’s turned on.
Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street.
Nuclear energy is transferred to electrical energy to provide electricity for our homes.
Answer:
i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right
Explanation:
Answer:
i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right
Explanation:
a) Calculate the standard reaction entropy for the combustion of methane to carbon dioxide and liquid water at 298 K. b) Calculate the standard reaction entropy for the hydrolysis of liquid water to form oxygen and hydrogen gas. c) Do your results in (a) and (b) agree with the general rule that reaction entropies are positive if there is a net formation of gas in a reaction, and negative if the is a net reduction of gas?
Answer: (a) [tex]\Delta S^{0}[/tex] = - 242.2J/K.mol
(b) [tex]\Delta S^{0}[/tex] = 163.34J/K.mol
(c) Yes
Explanation: Entropy is the measure of randomness or disorder of a system. Standard Entropy has the symbol [tex]S^{0}[/tex].
Mathematically, Entropy is defined as
[tex]\Delta S^{0}=\Sigma S^{0}(products)-\Sigma S^{0}(reagents)[/tex]
Each substance has its own entropy value.
(a) Combustion of Methane:
[tex]CH_{4}+2O_{2}[/tex] ⇒ [tex]CO_{2}+2H_{2}O[/tex]
Using standard entropy table, entropy will be:
[tex]\Sigma S^{0}(products)=214+2(69.91)[/tex] = 353.8
[tex]\Sigma S^{0}=186.264+2(205.138)[/tex] = 596.54
[tex]\Delta S^{0}=[/tex] 353.8 - 596.54
[tex]\Delta S^{0}=[/tex] - 242.2
Standard Entropy for combustion of methane is [tex]\Delta S^{0}=[/tex] - 242.2 J/K.mol.
(b) Hydrolysis of Water:
[tex]H_{2}O_{(l)}[/tex] ⇒ [tex]H_{2}_{(g)}+1/2O_{2}_{(g)}[/tex]
[tex]\Sigma S^{0}(products)=130.684+0.5(205.138)[/tex] = 233.253
[tex]\Sigma S^{0}(reagents)=69.91[/tex]
[tex]\Delta S^{0}=[/tex] 233.253 - 69.91
[tex]\Delta S^{0}=[/tex] +163.34
Standard Entropy for hydrolysis of water is [tex]\Delta S^{0}=[/tex] + 163.34 J/K.mol
(c) Yes, the results prove the general rule: Reactions Entropies are positive for net formation of gas and negative for net reduction of gas. This happens because, as entropy is the measure of disorder, the entropy for gases are greater than for liquids and solids. So, when there is formation of a gas, Entropy increases and when there isn't, entropy decreases.
Question 4 of 35
What did Thomson discover as a result of his experiments with cathode ray
tubes?
A. Electrons are found within electron clouds of atoms.
B. Each atom has a positive nucleus at its center.
C. Electrons travel along circular paths within atoms.
D. Atoms are made up of smaller subatomic particles
Answer:
D
Explanation:
Answer:
D Atoms are made up of smaller subatomic particles
Explanation:
I just took the quiz, I hope this helps!
What will happen to the following equilibrium if Cl2
was removed ?
4HCI(9) + O2(9) = 2012(9) + 2H20(9)
The following equilibrium will shift in the direction of the product:
Further explanationGiven
Reaction
4HCl + O₂ → 2H₂O + 2Cl₂
Cl₂ was removed
Required
Equilibrium changes
Solution
Reaction = - action
adding the products ⇒ Shifts in the direction of the reactants
reducing the products ⇒Shifts in the direction of the products
Cl₂ as a product, so if Cl₂ is taken or reduced, the reaction will try to maintain system equilibrium by moving to the right (product formation) ⇒ Shift in the direction of the product:
A common carboxylic acid used in cooking is acetic acid, if its composed of two carbons whats its iupac name
Answer:
ethane
Explanation:
Ethane is an organic chemical compound with chemical formula C ₂H ₆. At standard temperature and pressure, ethane is a colorless, odorless gas. Like many hydrocarbons, ethane is isolated on an industrial scale from natural gas and as a petrochemical by-product of petroleum refining
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(
)BaO2 + (
)H2SO4 → (
)H2O2 + (
)BaSO4
Answer:
1
1
1
1
Explanation:
the equation is balancing
_______ are characterized by having high melting and boiling points as well as being solid at room temperature
A. Iconic lattices
B. Giant covalent structures of ionic lattices
C. Giant covalent
D. Lone pairs
Answer:
C. Giant covalentGiant covalent are characterized by having high melting and boiling points as well as being solid at room temperature. Hence, option C is correct.
What is a covalent bond?A covalent bond shares one or more pairs of electrons between two atoms.
Giant covalent structure:
Polythene: long chains of atoms that are able to rotate along the bonding axis.
Graphite: layers of (hexagonal) carbon sheets; each individual sheet are rigid (allows no rotation.)
Silicon dioxide: three-dimensional (tetrahedral) network of carbon and oxygen atoms; the entire network is very rigid (allows no rotation.)
Diamond: three-dimensional (tetrahedral) network of carbon atoms and is very rigid.
Hence, giant covalent are characterized by having high melting and boiling points as well as being solid at room temperature.
Learn more about covalent bond here:
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HELPPPPPPPPP 35 POINTSSSSSS!!!!!
A metal is oxidized if it’s converted from its metallic form to make a compound, and it’s reduced if it’s converted back to its metallic form.
FILL IN THE BLANKS with either "reduce" or "oxidize"
Magnesium is able to copper, and copper is able to magnesium.
Zinc is able to magnesium, and magnesium is able to zinc.
Copper is able to zinc, and zinc is able to copper.
Answer:
oxidize
Explanation:
d = 7 V = 950 cm M = 95 g
0.1 g/cm3
0.1 cm3
90,250 g
90,250 g/cm3
Answer:
daddy chill
Explanation:
What is the name of the compound with the formula LiNO3?
Answer:
Lithium nitrate
Explanation:
Lithium nitrate is an inorganic compound with the formula LiNO3. It is the lithium salt of nitric acid (an alkali metal nitrate).
A silver bar has a mass of 368g. What is the volume in cm³ of the bar? The density of silver is 19.5g/cm³.
Answer:
18.87 cm³Explanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question we have
[tex]volume = \frac{368}{19.5} \\ = 18.871794..[/tex]
We have the final answer as
18.87 cm³Hope this helps you
How many grams of NaCl are needed to make 300ml of a 2% solution
Answer:
2grams as per the question
Please help, it’s much appreciated
If the hydrogen ion concentration,
[H+], in a solution is 2.65 x 10-2 M,
what is [OH-]?
Answer: acidic
Explanation:
Answer:
3.77 x 10^-13 M
Explanation:
what tools are used specifically for earth science
Geologic Tools. Geologists use a lot of tools to aid their studies. Some of the most common tools used are compasses, rock hammers, hand lenses, and field books.
hope this helped <3
HELPPPPPPP
is this chemical or physical reaction
Answer:
Chemical reaction
Explanation:
It's creating a whole other substance
if you aint stephanie dont anwer
Answer:
wsp
Explanation: