Answer:
Hof(X) = - 1474.9 KJ/mol
Explanation:
The reaction equation given to us is:
2 X + 5 O2 (g) --> 4 CO2 (g) + 6 H2O (g) ∆H = -75.0 kJ
Now, the equation for the standard enthalpy of formation of the reaction is written as follows:
ΔH = 4*Hof(CO2(g)) + 6*Hof(H2O(g)) - 2*Hof(X) - 5*Hof(O2(g))
where,
ΔH = - 75 KJ
Hof(CO2(g)) = Standard Heat of Formation of CO2(g) = -393.5 KJ/mol
Hof(H2O(g)) = Standard Heat of Formation of H2O(g) = -241.8 KJ/mol
Hof(X) = Standard Heat of Formation of X = ?
Hof(O2(g)) = Standard Heat of Formation of O2(g) = 0 KJ/mol
Therefore,
-75 KJ = (4)(-393.5 KJ/mol)+ (6)(-241.8 KJ/mol) - (2)(Hof (X)) - (5)(0 KJ/mol)
- 75 KJ + 3024.8 KJ = - (2)(Hof(X))
Hof(X) = -2949.8 KJ/2 mol
Hof(X) = - 1474.9 KJ/mol
The sun's energy influences climate in different ways. For example, the latitudes at the equator receive more intense energy from the sun and therefore have warmer temperatures. How does the sun's energy MOST DIRECTLY influence precipitation in an area?
Answer:
The Sun's energy is transferred as both light and heat energy, that raises the temperature of an area receiving the Sunlight. The increased temperature results in the evaporation of water from surfaces and water bodies, such that the mass of water vapor rises up into the atmosphere and condenses when it gets away from the ground heat to the cooler and higher altitudes
When there is a situation of low pressure, the wind blows into the low pressure, where, in the equator, comprises of high temperature air which could contain considerable amount of vapor from the neighboring water bodies, resulting in the eventual rise of very moist air, up into the atmosphere, that condenses at low temperature at the high altitudes, accumulate into larger masses of liquid water, and fall as rain
Explanation:
what is a Contraction science
Answer:
Contraction. (Science: physiology) a shortening or reduction in size, in connection with muscles contraction implies shortening and/or development of tension. Origin: L. Contractus = drawn together.
Explanation:
hope this helped:)
Sodium and Chlorine are both elements,
so the only contain one type of atom.
Is this true or false?
True
Answer:
False
Explanation:
1 teaspoon is Benefiber is added to 1 1/2 cups of water. Which of the following correctly describes what is formed?
O A. The chemical reaction between water and Benefiber allows one substance to dissolve in the other.
B. Water and Benefiber combine to form a precipitate.
o C. Benefiber is the solute in the solution that is formed.
D. Water is the solution in the solvent that is formed.
Explanation:
(A) Manganese salts give a grey borax bead test in reducing flame.
(B) From a mixed precipitate of AgCl and AgI, ammonia solution dissolves only AgCl due to the formation of [Ag(NH
3
)
2
]Cl.
(C) Ferric ions give a prussian blue precipitate on adding potassium ferrocyanide solution (D). On boiling the solution having K
+
, Ca
2+
, and HCO
3
−
ions, we does not get a precipitate of K
2
Ca(CO
3
)
2
The circumference of the earth is 25,000 mi at the equator. What is the
circumference in km?
Answer:
40233.6
hope this helps
plz mark brainleist
Definition of periodic trends
Answer:
.Periodic trends are specific patterns in the properties of chemical elements that are revealed in the periodic table of elements. Major periodic trends include electronegativity, ionization energy, electron affinity, atomic radii, ionic radius, metallic character, and chemical reactivity.
Methane gas reacts with oxygen by combustion. How many moles of methane are needed to produce 3.5x10^-4 moles of carbon dioxide?
Answer:
3.5×10^-4 moles of methane is needed.
~~20 points~~ What is the mass number of an element which has 43 protons, 46 neutrons, and 43 electrons?
a. 132
b. 3
c. 86
d. 83706
e. 89
f. -46
g. there is not enough information given to correctly answer the question
Answer:
e. 89
Explanation:
The mass number is the number of protons and neutrons in an atom. It doesn't include electrons.
43 + 46 = 89
convert 3.01€22 molecules of O²(a) mole of O²) ,volume at S.T.P,no of Oxygen atom. (d) mass
Answer:
a )0.05 moles of O₂
b) 1.1207 dm³
c) 0.3× 10²³ atoms of oxygen
d) 1.6 g
Explanation:
Given data:
Number of molecules of O₂ = 3.01 × 10²² molecules
Number of moles of O₂ = ?
Volume of oxygen at ATP = ?
Number of oxygen atoms = ?
Mass of oxygen = ?
Solution:
The given problem will solve by using Avogadro number.
"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance". The number 6.022 × 10²³ is called Avogadro number.
Moles of oxygen:
1 mole = 6.022 × 10²³ molecules
3.01 × 10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.05 moles of O₂
Number of atoms of oxygen:
1 mole = 6.022 × 10²³ atoms
0.05 mol × 6.022 × 10²³ atoms /1 mol
0.3× 10²³ atoms of oxygen
Volume of oxygen:
1 mole of oxygen at STP occupy 22.414 dm³
0.05 mol × 22.414 dm³ / 1mol
1.1207 dm³
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 0.05 mol × 32 g/mol
Mass = 1.6 g
How many grams of sodium chloride must be added to make 400 mL of a 0.600 M sodium chloride?
Answer:
14.0 g
Explanation:
nnandff
The mass in grams of sodium chloride must be added to make 400 mL of a 0.600 M sodium chloride is 14 grams.
How do we calculate mass from moles?Mass of any substance will be calculated by using their moles as:
n = W/M, where
W = required mass
M = molar mass
Also we know that, molarity of any solution is define as the number of moles of solute present in per liter of the solution.
M = n/V, where
M = molarity of NaCl = 0.600M
V = Volume of solution = 400mL = 0.4L
n = (0.6)(0.4) = 0.24moles
Now mass of NaCl will be calculated by using the first equation as:
W = (0.24mol)(58.44g/mol) = 14grams
Hence required mass of NaCl is 14 grams.
To know more about moles, visit the below link:
https://brainly.com/question/15374113
Microwave Miracle: Patrick believes that if fish eat microwaved food then they be able to swim through a maze faster. He decides to perform an experiment by placing fish food in a microwave for 20 seconds. He has the fish swim through a maze and records the time it takes for each one to make it to the end. He feeds the microwaved food to 10 fish (group A) and gives regular food to 10 others (group B). After 1 week, he has the fish swim through the maze again and records the times for each. Which fish are in the control group? * Group A Group B Microwaved Food Non-microwaved Food
Answer:
Group B
Explanation:
The fish in group B are those in the control group.
A control group during an experiment represents a group of the subject that is subjected to all experimental variables except the independent variable - the manipulate-able variable that is supplied by the experimenter which directly affects the dependent variable.
In this case, the independent variable is the type of food given to the two groups of fishes - microwaved or regular food while the dependent variable is the time it takes for the fishes to swim through the maze. Since the focus of the experiment is to see if microwaved food enhances the swimming speed of fishes, the group of fish that receives microwaved food would represent the treatment group while those that received regular food would be the control group.
Hence, group B represents the control group.
What two positions would the moon be when we have the lowest tidal range?
Answer:
Quarter and half moons
Explanation:
1.if I drove 40 miles west in 2 hours what is my velocity
2.find the time it takes for a bird that travels 15 miles per hour for 3 hours
1. v= 20 miles/hr
2. d = 45 miles
Further explanationVelocity is a vector that has both magnitude and direction
Velocity is the ratio of distance per time
Can be formulated :
[tex]\tt v=\dfrac{d}{t}[/tex]
v , m/s
d , m
t, s
1. d = 40 miles
t = 2 hr
[tex]\tt v=\dfrac{40~miles}{2~hr}\\\\v=20~miles/hr[/tex]
2. maybe you meant the distance traveled
v = 15 miles/hr
t = 3 hr
[tex]\tt d=v\times t\\\\d=15\times 3\\\\d=45~miles[/tex]
2a. Density is the relationship between mass and volume. Density has
many uses but is most commonly used to help determine the identity of
an unknown substance. Specifically for copper the proportion is
approximately 8.96 grams for every mL of copper. Approximately how
much volume (mL) would 29 grams of copper have? While it is helpful for
you to show all work, you MUST provide rationale for your thinking and
explanation for each of your steps.
The volume of copper : 3.24 ml
Further explanationDensity is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of mass
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:
[tex]\large{\boxed {\bold {\rho~=~ \frac {m} {V}}}}[/tex]
ρ = density , g/cm³ or kg/m³
m = mass , g or kg
v = volume , cm³ or m³
A common example is the water density of 1 gr / cm³
The density of copper : 8.96 gr/ml
mass of copper : 29 g
then the volume :
[tex]\tt V=\dfrac{m}{\rho}\\\\V=\dfrac{29~g}{8.96~g/ml}\\\\V=\boxed{\bold{3.24~ml~or~3.24~cm^3}}[/tex]
What are the characteristics of metals vs. non metals?
Answer:In the picture
Explanation: None
What is the density of an object of an object having a mass of 6.0 grams and a volume of 35 cm3?
Answer:
0.17 ( 2 s.f.)
Explanation:
d=m/v
=6/35
=0.1714285
=0.17
Answer:
Hey bro
Explanation:
I don't like boys and the answer most definitely is 69
2(NaHCO3) how many atoms of hydrogen
Answer:
2 hydrogen atoms
2 Na atoms
2 carbon atoms
6 oxygen atoms
Answer:
11
Explanation:
Which of the following statements is true about neutrons? *
a)They have a neutral charge and are found in an atom's nuclues
b)They have a negative charge and are found in an atom's nucleus
c)They have a positive charge and are found in the orbitals of an atom
d)They have a neutral charge and are found in the orbitals of an atom
Answer:
A
Explanation:
Neutron, neutral subatomic particle that is a constituent of every atomic nucleus except ordinary hydrogen. It has no electric charge and a rest mass equal to 1.67493 × 10−27 kg—marginally greater than that of the proton but nearly 1,839 times greater than that of the electron.
a patient is prescribed tigan capsules for vomiting. The drug is available in the form of 300.0 mg tigan/capsules ,and is administered in 4.0 doses/day of 1 capsule/dose. How many g Tigan does the patient recieve in 2.0 days?
The patient recieves 2.4 g Tigan in 2 days
Further explanationIn finding the conversion units, we can multiply and eliminate the same units so that we can get the desired quantity or unit.
In this case, it is expected that the number of Tigan is known in 2 days, so we just need to multiply the numbers that are known
[tex]\tt =300\dfrac{mg}{capsules}\times \dfrac{1~capsules}{dose}\times 4.0\dfrac{doses}{day}\times 2.0~days\\\\=300\times 1\times 4.0\times 2.0~mg=2400~mg=\boxed{\bold{2.4~g}}[/tex]
Lithium (Li) and oxygen (O) are both in period 2. They both have _____.
the same number of protons
two electron shells
the same number of electrons
similar properties
Answer:
So Lithium (Li) and Oxygen (O) are both have two electron shells
Explanation:
Answer:
Lithium (Li) and oxygen (O) both have two electron shells.
Explanation:
Answered correct on my test.
Also I'm aware you asked this around 4 months ago although I still wanted to answer so those who may need an answer in the future can reflect on this response and get the correct answer they deserve. Thanks! Happy New Year everyone. <3
how do birds fly in the south
Answer:
with there wings
Explanation:
birds have wings that flap up and down when they fly and this process repeats over and over
***20 pts***
If you had 3.02 grams of Sodium (Na), how many moles would that be?
ANSWER W STEPS IF NOT REPORTED
Answer:
0.131 mol
Explanation:
To convert grams to moles, you need to use the molar mass. The molar mass is the mass number. You can find this on the periodic table. The molar mass of sodium is 22.990 g/mol.
(3.02 g)/(22.990 g/mol) = 0.131 mol
A car travels 100 m while decelerating to 8 m/s in 5 s.
initial speed is 32
b) What was it's acceleration?
look at the three solid blocks made of the same material and with the exact same dimensions which block has the greatest mass
Answer:
where are the solid blocks?
Explanation:
1) Describe the characteristics of molecular compounds that affect their particular physical
properties. (Include melting/boiling points, strength of bonds, reactivity, and 3-dimensional
geometry.)
How much heat is absorbed when 500 g of
water, c = 4.184 J/g°C, goes from 25.0 °C to
35.0 °C?
Answer:
Assume that the coffee has the same density, 0.997 g/mL ... One liter of water has a mass of 1 kg and a specific heat of 4.184 J/(g °C).
Explanation:
what is the scientific method?
A) the process of proving a theory
B) a way of analyzing data
C) a method of testing an idea
D) the steps required to form a hypothesis
Answer:
C- a method of testing an idea
Significant figures are the digits within the number that help determine
accuracy.
о
True
о
False
Answer:false
Explanation:
Which is a compound?
A. smog
B. sea water
C. air
D. magnesium
E. salt
Answer:
The answer is D) Magnesium
Explanation:
Because smog is a mixture
sea water is a mixture
air is an element
And salt solvent
It can only be D
What term describes the smallest unit that can perform all of the functions necessary for life
Answer:
Cell
A cell is the smallest unit of a living thing. Cells are the basic building blocks of all organisms