Answer:
[tex]\mathbf{-1.12 \times 10^4 \ kJ/mol}[/tex]
Explanation:
Given that:
mass (m) of the sample = 1.02 g
number of moles of stearic acid [tex]=\dfrac{mass}{molar mass}[/tex]
[tex]= \dfrac{1.02 \ g}{284.49 \ g/mol} \\ \\ = 0.000358 \ moles[/tex]
The change in temp. [tex]\Delta T = 4.26^0 \ C[/tex]
heat capacity of the calorimeter (c) = 9.43 kJ/° C
Thus, heat due to reaction = cΔT
= 9.43 kJ/° C × 4.26° C
= 40.17 kJ
The heat in kJ/mol = [tex]\dfrac{40.17 \ kJ}{0.00358 \ mol}[/tex]
= 11204.23 kJ/mol
= 1.12 × 10⁴ kJ/mol
As a result of the reaction is exothermic, the heat reaction of the combustion is:
[tex]\mathbf{-1.12 \times 10^4 \ kJ/mol}[/tex]
Which solution is a homogeneous mixture?
sand and water
salt and water
salad dressing
soil
Answer:
soil
Explanation:
d. What do all of the molecules in the table have in common?
Answer:
They all have a certain amount of protons electrons and neutrons.
17.4. A gas is found to have a density of 8.00 g/L. Find the volume of the gas in a balloon that
has a mass of 24 grams.
A. 192 liters
B. 3 liters
C. 0.3 liters
D. 32 liters
what is the answer?
Answer:
3 litersExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
We have
[tex]volume = \frac{24}{8} = 3 \\ [/tex]
We have the final answer as
3 litresHope this helps you
The parts of DNA that give instructions for making proteins are called ________.
a genes
b dominant trait
c recessive trait
d mutation
Answer:
A
Explanation:
Each DNA sequence that contains instructions to make a protein is known as a gene. The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans.
Calculate the heat energy released when 21.1 g of liquid mercury at 25.00 °C is converted to solid mercury at its melting point.
Constants for mercury at 1 atm
heat capacity of Hg(l) 28.0 J/(mol⋅K)
melting point 234.32 K
enthalpy of fusion 2.29 kJ/mol
3. When looking at a potential energy graph, how do you know if a reaction is
exothermic or endothermic?
Answer:
The correct answer is -
if the potential energy of reactants is less than the potential energy then it is an endothermic reaction and if the potential energy of reactants is more than the products it is an exothermic reaction.
Explanation:
The potential energy graph represents the energy change in a reaction as it progresses. In the initial part of the reaction, the energy shows are the energy of reactants that takes part in the reaction, and in the later phase, the energy has represented the energy of products of the reaction.
To find the reaction if it is endothermic or exothermic one can see if the potential energy is increased or decrease with the progress of the reaction. if the reaction is increasing in energy with the progress then it is endothermic and exothermic in less energy.
explain how temperature and mass affect the appearance of stars
Answer:
If the star has smaller mass than the Sun, it can fuse hydrogen into helium for at least a trillion years. The larger a star, the shorter its life because it fuses hydrogen into helium much more quickly. A star whose mass is more than 20 Suns will run out of hydrogen in only a few hundred million years.
Which of the following astronomical bodies would most likely be the largest?
1. A dwarf star from a nearby solar system
2. A comet
3. One of the gas giants in our solar system
4. Ganymede, the largest moon of Jupiter
Answer:
1
because a dwarf star will seemlarge because of the in ability of any human being to see d sun
Please balance the equation C7H16 + CoF3 = C7F16 + HF +CoF2
with solutions
b. how many grams of CH6 is needed to react with 20.0 grams of HF?
C. how many particles of CoF3 is needed to react with 40.0 grams of CzF16?
d. how many grams of CH16 will be produce from 2.03 x 10 molecule of CoFs?
e. Find the Limiting reactant and exXcess reactant in CF16?
6g of CH16
6g of CoFa
f. Find the theoretical yield from CzFi6?
g. What is the percent yield of C;F16 if the actual yield is 1.28 g ?
Think
about the physical properties used to identify elements as either metal,non-metals, or metalloids. Write
Imagine that you are asked to classify a group of elements as either metal, non-metals, or metalloids.
Explain how you would use their physical properties to accomplish this task.
Be sure to –Address the prompt, provide support, and conclude your thoughts. Write legibly and concisely.
Answer:
The elements can be classified as metals, nonmetals, or metalloids. ... Elements are further classified into metals, non-metals, and metalloids based on their properties, ... when they undergo chemical reactions They normally do not accept ... Most metal oxides are basic oxides and dissolve in water to form .
Explanation:
There is a bottle of KCl solution: the volume is 35 mL; its molarity is 3.0 M.
After diluting it into final volume 200 mL, what is the molarity (in M) now?
Answer:
0.525 M
Explanation:
As the problem deals with a dilution process, we can use the following formula:
C₁V₁=C₂V₂Where subscript 1 stands for initial concentration and volume, while 2 stands for the final conditions. Meaning that in this case:
C₁ = 3.0 MV₁ = 35 mLC₂ = ?V₂ = 200 mLWe input the data given by the problem:
3.0 M * 35 mL = C₂ * 200 mLAnd solve for C₂:
C₂ = 0.525 MWhat mineral property is being tested below?
Answer:
Streak
Explanation:
Hope it Help
Thanks me later
Metals are cunductor of heat and electricity prove this statement
Answer:Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.
Explanation:
What is the empirical formula of the following molecular formula: C3H6
Answer:
CH2
Explanation:
The empirical formula is the lowest ratio form of a compound. You can divide both C and H by 3 to get to CH2.
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place
over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
molecules will speed up
Explanation:
what is the molecular formula for a compound with the empirical formula: K2SO4 and a molecular mass of 696g
Answer:
K8S4O16 or K8(SO4)4 depending on if the SO4 is supposed to represent sulfate or not
Explanation:
Find the molar mass of K2SO4 first:
2K + S + 4O ≈ 174 g/mol
Divide the goal molar mass of 696 by the molar mass of the empirical formula:
696 / 174 = 4
This means you need to multiply everything in the empirical formula by 4:
K2SO4 --> K8S4O16 or K8(SO4)4 depending on if the SO4 is for sulfate or not
K₈S₄O₁₆ is the molecular formula for a compound with the empirical formula K₂SO₄ and a molecular mass of 696 g.
What is empirical formula?Empirical formula of a compound is defined as the simplest whole number ratio of atoms which are present in a compound.It does not make any mention of the arrangement of atoms or the number of atoms. The empirical formula gives information about the ratio of number of atoms which are present in a compound.
Molecular formula is determined from the empirical formula by dividing the molar mass of a compound by the empirical formula mass. The resultant which should be a whole number or very close to the whole number , then the subscripts are multiplied by the whole number to get the molecular formula.
In this case molar mass of K₂SO₄ that is 696 is divided by empirical formula mass which is 174.25 g which gives 4 , subscripts of K₂SO₄ is multiplied by 4 to give K₈S₄O₁₆ .
Thus, the molecular formula of compound is K₈S₄O₁₆.
Learn more about empirical formula,here:
https://brainly.com/question/14044066
#SPJ6
What is the balanced molecular equation and balanced chemical equation for NaSO4 and KNO3?
Answer:
=KSO4+Na2(NO3)2
Explanation:
the answer is true using this chemical equation balancer
What would this mechanism look like?
Answer:
Not sure sorry :(
Explanation:
Ali says the climate of a town is rainy because it is raining outside today. Is she correct? In one or two sentences, explain why Ali is or is not correct about the climate of the town.
Answer:
Ali is incorrect.
Explanation:
Ali is wrong because the climate is a study of the weather pattern over a long period of time. You cannot look outside one day and determine the climate because the climate is long-term.
She could say the weather is rainy, because that is short term, but not the climate.
Which type of formula shows an element symbol for each atom and a line for each bond between atoms?
structural
molecular
empirical
ionic
Answer: structural
Explanation:
When metals and non metals combine in fixed proportion then a chemical compound is formed. Structural formula shows an element symbol for each atom and a line for each bond between atoms. The correct option is option A.
What is chemical formula?Chemical formula is a formula where cation and anion combine to form a molecule in fixed proportion. Metals combine in form of cation and non metals combine in form of anion.
Cation is the species that give electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral.
Out of given structural is a 3D representation of any chemical formula, in which symbol of each element is shown .Along with symbol line for each bond between atoms is also shown.
Therefore, the correct option is option A.
To learn more about Chemical formula, here:
https://brainly.com/question/28522480
#SPJ2
Which of the following chemical reactions will produce a precipitate?
3 KBr + AlPO4 → K3PO4 + AlBr3
Na2CO3 + CaCl2 → CaCO3 + 2 NaCl
NH4OH + KCl → KOH + NH4Cl
ZnCl2 + Mg2SO4 → ZnSO4 + MgCl2
Answer:
Na2CO3 + CaCl2 → CaCO3 + 2 NaCl
Explanation:
A double displacement reaction is a type of metathesis reaction in which two reactants exchange ions to form two new compounds. Double displacement reactions usually involve reacting two soluble salts in aqueous solution resulting in the formation of two products: a soluble salt and an insoluble salt that is produced as a precipitate.
If the reaction of two soluble compounds does not produce a precipitate, the reaction does not result in the formation of a product as basically, all the ions are mixed together in the reaction vessel.
From the given reactions above:
1. 3 KBr + AlPO4 → K3PO4 + AlBr3
The reaction does not proceed to product formation as the two products are all soluble salts.
2. Na2CO3 + CaCl2 → CaCO3 + 2 NaCl
The reaction occurs as one of the products, CaCO3 is insoluble as is produced as a precipitate.
3. NH4OH + KCl → KOH + NH4Cl
The reaction does nott occuras the products are all soluble in water.
4. ZnCl2 + Mg2SO4 → ZnSO4 + MgCl2
The reaction does not occur as the products are all soluble in water.
Fires are classified into various classes and as such different types of portable fire extinguishers must be used. The theory behind portable fire extinguishers is that the fire can be extinguished by removing any or more of the following four elements:
Fuel, Heat, Oxygen, Chain Reaction.
Identify the extinguishing mechanism and the classe(s) of fires they are used to extinguish for the following types of fire extinguishers:
ABC Powder, Carbon dioxide, Foam, Water.
Answer:
Explanation:
ABC Powder: sprays a very fine chemical powder. This acts to blanket the fire and suffocate it. Class A, B, C fires
Carbon dioxide: extinguishes CO2. By doing so, it removes oxygen from the fire, effectively suffocating it of oxygen. Class B fires
Foam: spray a type of foam that expands when it hits the air and blankets the fire. This prevents the vapors from rising off the liquid to feed the fire, thus starving it of fuel. Class A and B
Water: releases microscopic water molecules that fight the fire on a variety of levels. the level of oxygen in the air is decreased, which helps to suffocate the fire. Class: most all
also, your fire classes:
Class A: freely burning, combustible solid materials such as wood or paper
Class B: flammable liquid or gas
Class C: energized electrical fire (energized electrical source serves as the ignitor of a class A or B fire – if electrical source is removed, it is no longer a class C fire)
Class D: metallic fire (titanium, zirconium, magnesium, sodium)
Class K: cooking fires – animal or vegetable oils or fats
Name 3 ways you can keep our community healthy?
Answer:
1. Practice healthy habits with kids in your life. ...
2. Engage in your school's efforts to encourage healthy practices. ...
3. Learn more about the decisions local officials are making that impact your environment. ...
4. Give back healthy options to your community.
Explanation:
Is anyone good at chemistry if so can someone help me please ?
(NO LINKS)
So, litmus paper is a qualitative tool for assessing the acidity or basicity of a substance (usually a solution). In general, blue litmus turns red in the presence of an acid, and red litmus turns blue in the presence of a base. They can't really tell you much more than that.
The solutions that are most likely acids are those that turn blue litmus red and do not evoke a color change in red litmus. A solution that turns red litmus blue or does not evoke a color change in blue litmus is likely not an acid. Using these criteria, solutions 4 and 7 are most likely acids since they both turn blue litmus red (and they cause no color change in red litmus).
The correct answer choice would thus be D.
Use Lewis theory to determine the chemical formula for the compound formed between Mg and Br. Group of answer choices Mg3Br2 Mg2Br3 Mg2Br MgBr2 MgBr
Answer:
MgBr2
Explanation:
(Mg^2+) + (Br^1-)
For every Mg we need 2 Br to balance out the compound.
Since magnesium has two outer electrons, it can donate one electron each to two bromine atoms having seven outer electrons in order for each of the atoms to have a complete octet.
Since the octet rule states that a stable atom must have eight electrons in its outermost shell, it follows that magnesium could give out two of its outermost electrons to two bromine atoms.
When that happens, each bromine atom which previously had seven electrons now have eight electrons, satisfying the octet rule. The correct formula of the compound is MgBr2.
Learn more: https://brainly.com/question/11527546
Which of these actions is an example of erosion caused by gravity?
A.
Constant freezing and thawing water forming a hole in an asphalt road
B.
Pieces of rock breaking off and falling from a mountain top
C.
Chemicals in the air dissolve minerals in a marble statue
D.
Plant roots widening cracks in a large granite rock
Answer:
The answer is a
Explanation:because yes
Answer: The answer is B.
Explanation: The rocks falling off is caused by gravity. Other options don't include effects of gravity; Therefore, B is correct.
Which of the following is a job that bones do?
a.provide the body with shape and protection
b.store minerals
c.produce supply of daily blood cells
d.all of the above
Answer:
a.Provide the body which shape and protection.
Explanation:
Bones usually gives us shape as well as protects our innner organs.
so if it helps don't forget to like and Mark me
Why is it expensive to bring electricity into urban areas?
Answer:
Power plants are not located in cities. Power has to travel a long distance over power lines to reach cities.
Explanation:
Calculate the OH-ion concentration of a 6.2x10-3 M HCIO3 solution.
Answer:
1.62x10⁻¹² M
Explanation:
HClO₃ is a strong acid, meaning that a 6.2x10⁻³ M solution has a molar concentration of H⁺ of 6.2x10⁻³.
With the above information in mind, we can calculate the pH of the solution:
pH = -log(6.2x10⁻³) = 2.21Now we can calculate the pOH of the solution, using the pH:
pOH = 14 - pHpOH = 11.79Finally we calculate [OH⁻], using the definition of pOH:
pOH = -log[OH⁻][OH⁻] = [tex]10^{-pOH}[/tex] = 1.62x10⁻¹² MPure substance uniform