Answer:
C
Explanation:
because then you'd be able to make a group to raid, run with you, and save more people.
4
In the Hatom , what is the correct order (arrangement) of energy levels
b) Name three substances which can undergo sublimation and deposition respectively
solid carbon dioxide, iodine, arsenic, and naphthalene
Explanation:
Examples of substances that undergo sublimation
Examples of solids that sublime are dry ice (solid carbon dioxide), iodine, arsenic, and naphthalene (the stuff mothballs are made of).
C3H8(g) + 5O2(g) ⟶ 3CO2(g) + 4H2O(g) H = -2220 kJ If 865.9 g of H2O is produced during this combustion, how much heat is generated? Do not include the negative sign in your answer. Express the answer to the nearest whole number, or round to the nearest ones place. The molar mass of H2O is 18.02 g/mol.
Answer:
3 × 10⁴ kJ
Explanation:
Step 1: Write the balanced thermochemical equation
C₃H₈(g) + 5 O₂(g) ⟶ 3 CO₂(g) + 4 H₂O(g) ΔH = -2220 kJ
Step 2: Calculate the moles corresponding to 865.9 g of H₂O
The molar mass of H₂O is 18.02 g/mol.
865.9 g × 1 mol/18.02 g = 48.05 mol
Step 3: Calculate the heat produced when 48.05 moles of H₂O are produced
According to the thermochemical equation, 2220 kJ of heat are evolved when 4 moles of H₂O are produced.
48.05 mol × 2220 kJ/4 mol = 2.667 × 10⁴ kJ ≈ 3 × 10⁴ kJ
What are the products of the balanced equation for the combustion of C8H17OH ?
A. 2C4H8(g)+H2O(l)
B. C8H17(s)+NaOH(aq)
C. 8CO2(g)+9H2O(l)
D. 8O2(g)+9H2O(l)
#7 which of the following decreases the rate of solubility of solid molecules in a solution?
Answer:
7. Option D
Explanation:
Solubility increases with the increase in temperature of the solution. It is so because the increase in temperature leads to increase in kinetic energy which then breaks the solute particles held together by intermolecular attractions.
Hence, option D is correct
The sky on Earth is blue because blue light is scattered through the atmosphere as the other colors of light pass
through undisturbed. Which nebulae have something similar happening?
Emission nebulae
Dark nebulae
Reflection nebulae
Planetary nebulae
Answer:
C
Explanation:
The electric field around a positive charge will:
The _______________________________________ of a plant cell are where photosynthesis takes place.
Answer:
chloroplast
Explanation:
Answer:
chloroplasts
Explanation:
What are the two types of bonding we have studied?
a. Metallic and covalent
b. Covalent and ionic
c. lonic and metallic
d. Molecular and metallic
What is the coefficient for hydrogen in the balanced equation for the reaction of solid tungsten(VI) oxide with gaseous hydrogen to form solid tungsten and liquid water?
Answer:
2
Explanation:
WO2(s) + 2H2(g) -> W(s) + 2H2O(l)
How many moles are there in 87.2 g of zinc fluoride?
Answer:
what I got was 0.8435160945347224 moles
Which of the following correctly shows a synthesis reaction involving potassium?
A. Br2 + 2KI → I2 + 2KBr
B. 4K + O2 → 2K2O
C. 2KClO3 → 2KCl + 3O22KClO3 → 2KCl + 3O2
D. 2K2O → 4K + O22K2O → 4K + O2
Answer:
B. 4 K + O₂ → 2 K₂O
Explanation:
Which of the following correctly shows a synthesis reaction involving potassium?
A. Br₂ + 2 KI → I₂ + 2 KBr
No, this is a single displacement reaction, in which Br displaces I from its salt.
B. 4 K + O₂ → 2 K₂O
Yes, this is a synthesis reaction, in which 2 elements combine to form a compound.
C. 2 KClO₃ → 2 KCl + 3 O₂
No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.
D. 2 K₂O → 4K + O₂
No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.
LEVEL 3
Write the correct order
of letters to the finish line.
A E B E C
Example:
ABCGH
G
H
N
eza
Not correct
Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]
A student is heating a crystal of alum to
determine the hydrate formula. If she removes
it from the heat before all the water has been
removed, what will happen to the calculated
hydrate formula?
A. It will not be affected by the error.
B. The mole ratio will indicate less water than was
actually present.
C. The mole ratio Will indicate less alum than was
actually present.
Aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce
a precipitate of copper (II) phosphate and aqueous potassium sulfate.
Answer:
CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄
Explanation:
The question is missing but I think it must be about writing and balancing the equation.
Let's consider the unbalanced equation for the reaction that occurs when aqueous copper (II) sulfate reacts with aqueous potassium fluoride to produce a precipitate of copper (II) fluoride (I fixed a mistake here) and aqueous potassium sulfate. This is a double displacement reaction.
CuSO₄(aq) + KF(aq) = CuF₂ + K₂SO₄
Since only K and F atoms are not balanced, we will get the balanced equation by multiplying KF by 2.
CuSO₄(aq) + 2 KF(aq) = CuF₂ + K₂SO₄
Tam a highly reactive alkali metal in period 3 with only one valence electron
O Sodium (Na)
Beryllium (Be)
Magnesium (Mg)
Answer:
Sodium (Na)
Helium
Magnesium (Mg).
Explanation:
From the periodic table, we will understand that the group 1 metals are the alkali metal. However, the period runs from left to right on the periodic table while the group runs from up to down in the periodic table. In period 3, the alkali metal present there with one valence electron in its outermost shell is sodium (Na).
The only noble gas exists in the last group, group zero of the periodic table. However, the only noble gas with two electrons in its outermost shell is called Helium
The ALkaline earth metals are group 2 metals. They are usually shiny metals and the ability to lose 2 electrons in their outermost electron shell. The alkaline earth metal located in period 3 is Magnesium (Mg).
Plz help me I am timed!!
Answer:
What do you need help with
Explanation:
Explanation:
okay I'll help but whats the question
The tablets were crushed, and 4.9993 g of the powder was transferred to a beaker and reacted with HCl. After filtration, the filtrate was transferred to a 100-mL volumetric flask and diluted with water. 20.00 mL of this stock solution were combined with 0.2 M Na3PO4. The resulting precipitate weighed 0.3451 g after drying. Calculate the moles of BiPO4 precipitated, the moles of Bi3 in the stock solution, and the mass of BSS per tablet.
Answer:
Explanation:
From the information given:
Mass of BiPO₄ = 0.3451 g
Number of moles of BiPO₄ = [tex]0.3451 \ g \ BiPO_4 \times \dfrac{1 \ mol \ BiPO_4}{303.95 \ g \ BiPO_4}[/tex]
[tex]= 0.001135 \ mol[/tex]
The number of moles of Bi³⁺ in 20.00 mL is:[tex]= 0.001135 \ mol \ BiPO_4 \times \dfrac{1 \ mol \ of \ Bi^{3+}}{1 \ mol \ BiPO_4}[/tex]
= 0.001135 mol of Bi³⁺
The number of moles of Bi³⁺ in 100 mL stock solution
[tex]= 0.001135 \ mol \ Bi^{3+} \times \dfrac{100 \ mL}{20.0 \ mL}[/tex]
[tex]= 0.005675 \ mol[/tex]
Mass of BSS in 4.9993 g tablets
[tex]m = 0.005675 \ mol \ Bi^{3+} \times \dfrac{1 \ mol \ BSS}{1 \ mol \Bi^{3+}} \times \dfrac{362.1 \ g \ BSS}{1 \ mol \ BSS}[/tex]
m = 2.055 g BSS
Mass of BSS in 5.0103 g (5 tables)
[tex]m = 2.055 g \ BSS \times \dfrac{5.0103 \ g}{4.9993 \ g}[/tex]
= 2.06 g
∴
The mass of BSS per tablet is [tex]=\dfrac{2.06 \ g}{5 \ tablet}[/tex]
= 0.412 g BSS/ tablet
Theses are all the points
I have left
Would you rather Go to jail for the rest of your life or go to prison for the rest of you life?
Answer:
I honestly don't know but I hope you get more points! ;D
Explanation:
For each of the environments below: (1) identify your system and surroundings and (2) predict whether it would be endothermic or exothermic.a.Wood burningSystem:Surroundings:Enthalpy Change:b.Water freezingSystem:Surroundings:Enthalpy Change:c.Sweat evaporatingSystem:Surroundings:Enthalpy Change:d.Chemical hand-warmerSystem:Surroundings:Enthalpy Change:
Answer:
A) Wood burning
system : Wood.
surroundings : atmosphere
Enthalpy : Exothermic
B) Water Freezing system
System : Refrigerator
surroundings : water in the refrigerator
enthalpy change : Endothermic
C) Sweat evaporating
System : Human being
surroundings : Air nearby
Enthalpy change : exothermic
D) Chemical Hand-warmer
system : Hand warmer pack
Surroundings : human palms
Enthalpy Change : Exothermic
Explanation:
A) Wood burning
system : Wood
surroundings : atmosphere
Enthalpy : Exothermic
This system give away energy to its surroundings hence its enthalpy change is exothermic
B) Water Freezing system
System : Refrigerator
surroundings : water in the refrigerator
enthalpy change : Endothermic
The system absorbs heat from what is put inside(surroundings ) of it hence this is na endothermic system
C) Sweat evaporating
System : Human being
surroundings : Air nearby
Enthalpy change : exothermic
This is an exothermic reaction ( enthalpy change ) because the system gives out heat to the surrounding
D) Chemical Hand-warmer
system : Hand warmer pack
Surroundings : human palms
Enthalpy Change : Exothermic
There is movement of heat from the system to the surrounding hence it is an exothermic reaction
In the oxidation of iron; how many grams of iron (III) oxide will be produced from 6.20 mol of Fe?
4Fe(s) + 3O2(g) --> 2Fe2O3(s)
Answer:
496 g of Fe₂O₃.
Explanation:
The balanced equation for the reaction is given below:
4Fe + 3O₂ —> 2Fe₂O₃
From the balanced equation above,
4 moles of Fe reacted to produce 2 moles of Fe₂O₃.
Therefore, 6.20 moles of Fe will react to produce = (6.20 × 2)/4 = 3.1 moles of Fe₂O₃
Finally, we shall determine the mass of 3.1 moles of Fe₂O₃. This can be obtained as follow:
Mole of Fe₂O₃ = 3.1 moles
Molar mass of Fe₂O₃ = (56 × 2) + (3×16)
= 112 + 48
= 160 g/mol
Mass of Fe₂O₃ =?
Mass = mole × molar mass
Mass of Fe₂O₃ = 3.1 × 160
Mass of Fe₂O₃ = 496 g
Therefore, 496 g of Fe₂O₃ were produced from the reaction.
How do you decrease the amount of energy storage molecules there are in an ecosystem?
a) increase sunlight
b) decrease sunlight
c) burn dead matter
d) bury dead matter
e) trap carbon dioxide
Decreasing sunlight will decrease the amount of energy storage molecules in an ecosystem.
What is Photosynthesis?This is the process in which green plants manufacture food in the presence of sunlight. Primary producers are involved in this process of providing energy to the ecosystem.
This therefore means that a decrease in sunlight means a decrease in photosynthesis and energy production.
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Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. What is the mass, in grams, of 133 mL of ethanol?
[tex]V = \text{133 mL}[/tex]
[tex]\rho = \text{0.789 g/mL}[/tex]
Required:[tex]m[/tex]
Solution:[tex]\rho = \frac{m}{V}[/tex]
[tex]m = \rho V[/tex]
[tex]m = (\text{0.789 g/mL})(\text{133 mL})[/tex]
[tex]\boxed{m = \text{105 g}}[/tex]
Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. 105g is the mass, in grams, of 133 mL of ethanol.
What is mass?In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the force that is applied. The change caused by a force applied is smaller the more mass a body has.
The kilogram, which would be specified as equivalent to 6.62× 10³⁴ joule second in terms of Planck's constant, is the unit of mass inside the International Units System (SI).
density = mass / volume
mass =density× volume
= 0.78× 1.33
=105g
Therefore, 105g is the mass.
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Nitrogen monoxide and hydrogen react to form nitrogen and water, like this: 2NO(g) 2H2(g) N2(g) 2H2O(g)Also, a chemist finds that at a certain temperature the equilibrium mixture of nitrogen monoxide, hydrogen, nitrogen, and water has the following composition:compoundpressure at equilibriumCalculate the value of the equilibrium constant Kp for this reaction. Round your answer to significant digits.
Answer:
hello your question is poorly written attached below is the complete question
answer : Kp = 4.75 * 10^-3
Explanation:
Kp = (76.4 * ( 50.3 )^2 )/ ((79.1)^2 * (80.6)^2 )
= 193298.876 / 40646490.2116
= 0.00475 ≈ 4.75 * 10^-3
attached below is the beginning part of the solution
what statement is the best description of a chemical bond
Answer:
A chemical bond holds atoms together.
how is acid different from base
Please help me l don’t understand please !!!!!!
Answer: C
Explanation:
he never had evidence in the first place that was nearly enough.
A percent composition analysis yields
22.6% phosphorus (P) and 77.4%
chlorine (CI). What is the empirical
formula for the compound?
А
B
P2C17
PCI:
Answer:
PCl₃
Explanation:
To determine the empirical formula of a compound, we need to follow a series of steps.
Step 1: Divide each percent composition by the atomic mass of the element
P: 22.6/30.97 = 0.729
Cl: 77.4/35.45 = 2.18
Step 2: Divide all the numbers by the smallest one, i.e. 0.729
P: 0.729/0.729 = 1
Cl: 2.18/0.729 ≈ 3
The empirical formula of the compound is PCl₃.
Which statement describes a homogeneous catalyst?
do
It is in a gaseous phase only. It is in the same phase as the reactants.
It is completely consumed by reactants.
It forms different products than the uncatalyzed reaction forms.
The statement which is given below describe a homogeneous catalyst.
"It is in the same phase as the reactants"
What is homogeneous catalyst?The catalyst which have similar phase to the reactant of the reaction is called homogeneous catalyst.
Mostly in homogeneous catalyst, catalyst present in liquid form.
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