Calculate the value of Delta H for the reaction CaCO3 --> CO2 + CaO from the following enthalpy changes:
Ca + C + 3/2 O2 --> CaCO3 ΔH = -1206.9 kJ
Ca + ½ O2 --> CaO ΔH = -635.1 kJ
C + O2 -->CO2 ΔH= - 393.5 kJ
Explanation:
crescents discuss wentz eg
Answer:
2,2,1,2
2 Ca + 2 CO2 + 1 O2 → 2 CaCO3
Explanation:
Got it right on Oddesyware!!!!
What dosage in grams per kilogram of body weight does a 134 lb woman receive if she takes two 275 mg tablets of penicillin?
How many 150. mg tablets should a 31 lb child take to receive the same dosage?
Answer:
The dosage is 0.0906 g/kgThe child should take 8.5 tablets to receive the same dosageExplanation:
First we convert 134 lb into kg:
1 lb = 0.453 kg134 lb * [tex]\frac{0.453kg}{1lb}[/tex] = 60.702 kgThen we convert 275 mg into g:
1000 mg = 1 g275 mg * [tex]\frac{1g}{1000mg}[/tex] = 0.275 gNow we can calculate the dosage in grams per kilogram of body weight, keeping in mind that two tablets are consumed:
(0.275 g) * 2 / 60.702 kg = 0.0906 g/kgAs for the second part, first we convert 31 lb into kg:
31 lb * [tex]\frac{0.453 kg}{1lb}[/tex] = 14.043 kgNow we calculate how many penicillin grams should be consumed:
14.043 kg * 0.0906 g/kg = 1.27 gWe convert 1.27 g of penicilin into mg:
1.27 g * 1000 = 1270 mgFinally we calculate how many 150 mg tables should be taken:
1270 mg / 150 mg = 8.5 tabletsWhich agent of erosion is probably at work in the area
Answer the above pic
i bet no one can solve this correctly with steps
Answer:
solution given:
log k=4-[tex] \frac{200}{t} [/tex]
so,
On comparison
∆S°/R = 4
∆ S° = 4R
mousam brother is correct
hope it helps you have a good day
Si tengo 56 gramos de amoniaco gaseoso (NH3) ¿Cuántos moles y moléculas (entidades elementales) podré obtener?
Answer: 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.
Explanation:
Given: mass of [tex]NH_3[/tex] = 56 g
Molar mass of [tex]NH_3[/tex] is 17.03 g/mol.
As moles of a substance are its mass divided by the molar mass. Therefore, moles of [tex]NH_3[/tex] are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{56 g}{17.03 g/mol}\\= 3.28 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules. Hence, number of molecules present in 3.28 moles of [tex]NH_3[/tex] are calculated as follows.
[tex]No. of molecules = no. of moles \times 6.022 \times 10^{23}\\= 3.28 mol \times 6.022 \times 10^{23}\\= 19.80 \times 10^{23}[/tex]
Therefore, we can conclude that 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.
What is the difference between chemical change and physical change
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
WHAT IS A ROCK?
Please put the answer below
DO ITTT NOWWWWWWWWWWWWWW
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Laughing gas can decompose into nitrogen and oxygen
Nitrous oxide decomposes into nitrogen and oxygen, according to 2 N2O (g) -> 2 N2 (g) + O2 (g). ... In an experiment, a stream of N2O is passed through a tube 25 mm in diameter and 20 cm long. The flow rate of the gas is 0.75 L/min.
Given that the nucleophilic substitution reaction used 5.0 mL of t-pentyl alcohol and 12.0 mL of conc. hydrochloric acid to produce t-pentyl chloride, what is the theoretical yield of t-pentyl chloride, in grams
Answer:
4.90 g
Explanation:
Given that:
volume of t-pentyl alcohol = 5 mL
the standard density of t-pentyl alcohol = 0.805 g/mL
Recall that:
density = mass(in wt) /volume
mass = density × volume
mass = 0.805 g/mL × 5 mL
mass = 4.03 g
Volume of HCl used = 12 mL
The reaction for this equation is shown in the image attached below.
From the reaction,
88.15 g of t-pentyl alcohol reacts with concentrated HCl to yield 106.59 g pf t-pentyl chloride.
4.03 g of t-pentyl alcohol forms,
[tex]= \dfrac{106.59 \ g \times 4.03 \ g}{88.15 \ g}[/tex] of t-pentyl chloride.
Therefore,
Theoretical yield of t-pentyl chloride = 4.90 g
Write the overall balanced equation for the reaction:
N2O4(g) + CO → NO(g) + CO2(g)+NO2(g)
Answer:
This reaction has infinite ways to be balanced
Explanation:
To balance this equation we can use the algebraic method:
N2O4(g) + CO → NO(g) + CO2(g)+NO2(g)
Where we write each molecule as a letter:
A + B → C + D + E
Then, we write the equations according the number of atoms of each molecule. That is:
Oxygen → 4A + B = C + 2D + 2E (1)
Nitrogen → 2A = C + E (2)
Carbon → B = D (3)
Then, we have to give 1 arbitral number for a letter. For example:
B = 1; D = 1
(1) 4A + 1 = C + 2 + 2E
4A = C + 2E + 1
2A = C + E (2) Twice (2):
4A = 2C + 2E
Subtracting (1) in (2)
C + 2E + 1 = 2C + 2E
C + 1 = 2C
1 = C
Si 1 = C:
4A + 1 = 1 + 2 + 2E
4A = 2 + 2E (1)
y:
2A = 1 + E (2)
Twice:
4A = 2 + 2E
As (1) and (2) are the same equation:
This reaction has infinite ways to be balancedFor example:
N2O4(g) + CO → NO(g) + CO2(g)+NO2(g)
What is the oxidation number of iron in FeO?
Answer:
+2
Explanation:
Answer:
2 electrons
Explanation:
In Iron (II) oxide, or Ferrous Oxide, or FeO, the Iron element (Fe) is bonded to the Oxygen, in the oxidation state of "2". This means that the Iron has accepted 2 electrons from the Oxygen.
Which gland would most likely have an issue with maintaining the breakdown of food?
the thyroid
the thymus
the pancreas
the ovaries
Answer:
OKAY EVERYONE STOP SAYING PANCREAS THATS WRONG
Explanation:
It is actually thyroid
Select all the correct answers.
Which statements demonstrate scientific research bias?
Jennifer studied the most convenient sample instead of obtaining a sample that better represented the entire population.
Tyler's conclusion was supported by his data, but it did not agree with his hypothesis.
Manny was presented with several possible research topics, and he chose the one he found most interesting.
Ellie carried out the same experiment four times, and she obtained the same result every time.
Brad expected a certain result from his experiment, so he interpreted his data in a way consistent with that result.
Answer:
1. Jennifer
Jennifer tried to cut corners and exclude a chunk of people from the population, making her results biased.
2. Brad
Brad was just seeing what he wanted to see, instead of facing the results of his experiment, which makes him scientifically biased. It's known as 'cherry-picking' informally.
Explanation:
Why are the rest not biased?
1. Tyler
You don't need your results and conclusion to agree with your hypothesis. A hypothesis is just your guess, it's not absolute and doesn't demonstrate bias if it doesn't agree with your conclusion.
2. Manny
He simply chose a topic he was interested in. It would be a different story if he already had a topic, but only chose information that agreed with his hypothesis, neglecting other pieces of information.
3. Ellie
This demonstrates no bias. She carried out an experiment and, according to experimental data, received the same results every time. She did not purposefully alter them to make them what she wanted to see.
Answer:
1. Jennifer
Jennifer tried to cut corners and exclude a chunk of people from the population, making her results biased.
2. Brad
Brad was just seeing what he wanted to see, instead of facing the results of his experiment, which makes him scientifically biased. It's known as 'cherry-picking' informally.
Explanation:
what are the physical properties of matter?
Answer:
Physical properties are typically things you can detect with your senses.
Explanation:
describe two sources of energy and explain how they work
please help me (50points)
Solar energy:-
In this way the energy generated through sun light with the help of solar panels and to be used in many works.
Wind energy:-
This is generated by moving turbines with windmills .It is used to create electric energy
How does an electric field change and influence its surroundings?
Answer:
The electric force acts over the distance separating the two objects. ... The space surrounding a charged object is affected by the presence of the charge; an electric field is established in that space. A charged object creates an electric field - an alteration of the space or field in the region that surrounds it.
Explanation:
4. Calculate the final temperature of 75.4 g water originally at 12.6 °C after it absorbs 3.85 kcal
of heat.
Answer:
63.7 °C
Explanation:
Step 1: Given and required data
Mass of water (m): 75.4 gInitial temperature (T₁): 12.6 °CAbsorbed heat (Q): 3.85 kcalSpecific heat capacity of water (c): 1 cal/g.°CStep 2: Calculate the final temperature of the water (T₂)
We will use the following expression.
Q = c × m × (T₂ - T₁)
T₂ = Q/c × m + T₁
T₂ = 3.85 × 10³ cal/(1 cal/g.°C) × 75.4 g + 12.6 °C = 63.7 °C
Balance this reaction:
___Naz3(PO4)+ ___K(OH) ---> ___Na(OH) +___K3(PO4)
a. Explain why the pie pans flew off the van de Graaf generator
b. Give a detailed explanation of why the rabbit fur and the plastic rod were attracted to each other after we rubbed them together but not before
c. Describe two things you could change to increase the force of electrical attraction between two objects (this is about Coluomb's Law).
Answer:
Static energy is an energy between two charges.
Explanation:
a). A van de Graff generator builds up a positive electric charge on the dome by separating the negative static electric charges from the positive static charge using a quickly moving belt. The positive charge collects on the large metal dome of the generator. When the charge builds up is large enough, a lighting like spark can shoot from the dome to a grounded discharge rod.
Like electric charges always repel each other, and oppositely electric charges will attract each other. When the aluminum pans are being charged by the van de Graff generator, then each of them attain the same positive polarity similar with the dome. Thus, positive charge starts to accumulate over the surface of each of the pie pan. Each aluminum pan repels the others. These repulsive forces between the pans are so strong that they succeed in overcoming the gravity force and thus the top of the pan is pushed away from the generator's dome.
b). Static electricity is produced by a concentration of negative and positive electric charges. Like charges pushes away each other while unlike charges pulls each other.
Objects generally have same numbers of positive charges as well as negative charges. And if there is any small imbalance in numbers of the charges on the object, it is charged.
Negative charges easily torn away from the materials like the fur or hair. Also, the negative charges are held on other materials like the plastics. If we rub a plastic rod with fur, the negative charges will get transferred from fur to rod. The rod gets negatively charged and the fur is positively charged. As a result, the rabbit fur and the plastic rod were attracted to each other.
c). Coulomb's law stated that :
[tex]$F=\frac{KQ_1Q_2}{d^2}$[/tex] .............(i)
where, [tex]$Q_1$[/tex] and [tex]$Q_2$[/tex] are the charges of two objects d is the distance between two objects.
As from the above equation, we can say that force of electrical attraction between two objects depends on the charges and the distance between objects.
1. The electrical force between two charged object is inversely proportional to the distance of separation between two objects.
Decreasing separation distance (d) between the objects will increase its attraction force.
2. And, increasing the charges of two objects(+ve and -ve) increases the force of attraction between two objects.
how many atoms are in 14 moles of cadium
Answer:
14x6.02x10^23=8.428x10^23 atoms
Answer:
atoms are in 14 moles of cadmium. Cadmium is present in some foods and is emitted when fossil fuels like as coal and oil is used, smoking cigarettes. It is used in craft glazes, metal batteries, and coatings. We know that 1 mole of Cadmium (Cd contains) 6.023*1023 atoms, which is Avogadro's number
Explanation:
Cuo
+ H2 → → Cu + + H20
colorless
water
black
powder
reddish
solid
gas
vapor
Explanation:
because there is 2 hydrogen atoms in the reactions side of the equation (you can tell because the H has a 2 in the subscript) you have to have 2 hydrogen atoms in the reactants side to help balance out the equation. and since the copper and oxygen atoms are already balanced there is no coefficient needed.
It takes 53.0 J to raise the temperature of an 11.0 g piece of unknown metal from 13.0∘C to 24.3 ∘C. What is the specific heat for the metal?
Answer:
51 = ( 8.2/1000)Kg ×S (11.5)
51×1000= 8.2 (11.5)S
S = 51000/94.3
S = 540.8 J/kg K
Explanation:
Soil comes in different colors.
Answer: yes they come in different colors.
Explanation:
Most shades of soil is mostly black,brown,red,gray,and white the color of soil and other properties including texture, structure, and consistency are used to distinguish and identify soil.
Final volume of a .50 M H3PO4 solution prepared from 50 mL of a 6 M H3PO4 solution
Answer:
600 mL
Explanation:
From the question given above, the following data were obtained:
Initial concentration (C₁) = 6 M
Initial volume (V₁) = 50 mL
Final concentration (C₂) = 0.5 M
Final volume (V₂) =?
Using the dilution formula (i.e C₁V₁ = C₂V₂) we can obtain the final volume as illustrated below:
C₁V₁ = C₂V₂
6 × 50 = 0.5 × V₂
300 = 0.5 × V₂
Divide both side by 0.5
V₂ = 300 / 0.5
V₂ = 600 mL
Thus, the final volume is 600 mL
10. An aqueous solution is made from 0.315 mol of Na,Cr2O7. If the volume of the
solution is .025 L, what is the molarity of the solution? (Answer with significant
digits. Example: 00.0)
Answer:
Its 12.6M
Explanation:
It came to the conclusion and got these answers
2.22
20.5
10
12.6
12.6 is the correct answer
The bullet train was traveling at a speed of 200mi/hr for 2 hours. What
was the total distance traveled? *
O 100mi
O 01mi
O 40mi
O 400mi
Answer:
Distance is speed x time
So 200 x 2 =400mi
A sample of polonium-210 has an initial mass of 390 milligrams (mg). If the half-life of polonium-210 is 36 days, how many mg of the sample remains after 72 days?
A.
392 mg
B.
195 mg
C.
97.5 mg
D.
48.75 mg
Answer:
C
Explanation:
I got this question right on my test.
The surface forces that change the surface of the earth are:
Faulting
Erosion
Volcanoes
Earthquakes
Glaciers
Living things
Weathering
Folding
Help ASAP!!
Answer:
erosion
glacier
living things
weathering
Explanation:
Calculate the volume, in milliliters, for the following:
.850 mol of NaNO3, from a .500 M NaNO3 solution
30.0 g of LiOH from a 2.70 M LiOH solution
Answer: The volume for 0.850 mol of [tex]NaNO_{3}[/tex] from a [tex]NaNO_{3}[/tex] solution is 1700 mL.
The volume of 30.0 g of LiOH from a 2.70 M LiOH solution is 464 mL.
Explanation:
Molarity is the number of moles of solute present in a liter of solution.
As given moles of [tex]NaNO_{3}[/tex] are 0.850 mol and molarity of [tex]NaNO_{3}[/tex] solution is 0.5 M. Hence, its volume is calculated as follows.[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\0.5 M = \frac{0.850 mol}{Volume}\\Volume = 1.7 L (1 L = 1000 mL)\\= 1700 mL[/tex]
Therefore, the volume for 0.850 mol of [tex]NaNO_{3}[/tex] from a [tex]NaNO_{3}[/tex] solution is 1700 mL.
As given mass of LiOH are 30.0 g from a 2.70 M LiOH (molar mass = 23.95 g/mol) solution. Hence, its number of moles are calculated as follows.[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{30.0 g}{23.95 g/mol}\\= 1.25 mol[/tex]
So, volume for LiOH solution is calculated as follows.
[tex]Molarity = \frac{no. of moles}{Volume (in L)}\\2.70 M = \frac{1.25}{Volume}\\Volume = 0.464 L (1 L = 1000 mL)\\= 464 mL[/tex]
Therefore, volume of 30.0 g of LiOH from a 2.70 M LiOH solution is 464 mL.
Name the part in red:
H2 + O2 -> H2O
Answer:subscript
Explanation:
