Answer:
Hydrocarbon fuels like methane (CH4) burn in the presence of oxygen to produce carbon dioxide and water. This process of combustion releases energy. When energy is released during the course of a chemical reaction, it is said to be an EXOTHERMIC reaction. The combustion of of methane gas releases 50.1 kJ/g.
true
The burning of methane in the presence of air is an exothermic reaction. The given statement is true.
Exothermic Reaction:
The chemical reaction in which heat energy is released during the reaction.
For example- the burning of 1 mole of methane in the air releases 810 kJ of heat energy.
[tex]\bold {CH_4 +2O_2 \rightarrow CO_2 + 2H_2 O}\ \ \ \ \ \ \ \bold{\Delta H = 810\ kJ}[/tex]
Therefore, the burning of methane in the presence of air is an exothermic reaction.
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The forces that hold molecules of metals together are stronger than the forces that hold molecules of non -metals together. This means that metals have
Answer:
Stronger bond as compared to non metals
Explanation:
Scientists say that photosynthesis and cellular respiration create a cycle that is essential to almost all life on Earth. Use your knowledge of these processes to explain how an oil spill that kills a large percentage of the photosynthetic organisms living in the ocean could affect humans.
Answer:
Explanation:
An oil spill is a catastrophic event in the environment. It can negatively affect both plants and wildlife while causing human suffering and economic losses. An oil spill needn't be on the scale of the Exxon Valdez or Deepwater Horizon disasters. The U.S. Environmental Protection Agency (EPA) estimates that 200 million gallons of used oil are disposed of improperly each year.
Spilled oil floats on the surface of the water, blocking the sunlight, from reaching the plants within the body of water. Spilled oil may also directly coat the leaves of plants -- where most of the work of photosynthesis occurs -- reducing or blocking out sunlight. Without sunlight, plants lack the energy needed to undergo photosynthesis.
An oil spill can impact photosynthesis by reducing water quality. Not only does the presence of oil directly poison the water, but the spill can kill sea life, birdlife and other wildlife that uses an aquatic habitat. A large die-off can increase bacteria levels and lower the pH of a body of water. The reduction in water quality can stress plants, essentially halting photosynthesis.
What happens to the ice pack over time?
Answer:
it melts?
I don't really know but I have 60% that I think the answer is correct
Are the forces on the parachutes balanced?
A. The parachutes fall at a constant speed, so the forces are balanced.
B. There is a change in motion, so the forces are balanced.
C. The parachutes fall at a constant speed, so the forces are unbalanced.
D. There is a change in motion, so the forces are unbalanced.
Answer:
When the parachute opens, air resistance becomes much greater than gravity. The forces are no longer balanced and this changes her speed.
Explanation:
Eventually the upward force of the air equals the downward force of gravity. When forces are balanced the speed remains constant.
How does the rock cycle work help use a easy understanding small summary
Answer: this is how it works
Explanation:
The magma bursts through Earth's surface in the form of a volcano. Heat and pressure deep in the Earth makes some rocks change to metamorphic rock. Layers of rock get squashed and packed together and gradually harden to form sedimentary rock. The igneous rock gets broken down by weather, and the cycle begins again.
organic acids are weaker than inorganic once it is true or false
Answer:
false
Explanation:
The complete combustion of acetic acid, HC2H3O2(I) to form water, H2O(I), and CO2(g), at constant pressure releases 871.7 kJ of heat per mol of acetic acid.
Write a balanced thermochemical equation if 5.0g of acetic acid will be used in the reaction.
HC2H3O2(I) + O2 --- H2O(I) + CO2(g) H= -871.7 kJ
Answer:
HC2H3O2(I) + O2(g) ---> H2O(I) + CO2(g) ΔH= -72.35 kJ
Explanation:
We know that 5.0 g of acetic acid will contain, 5.0g/60 g/mol = 0.083 moles of acetic acid
Now from the reaction equation;
1 mole of acetic acid evolved -871.7 KJ of heat
0.083 moles of acetic acid will evolve 0.083 * -871.7 = -72.35 KJ
For 5.0 g of acetic acid, we can write;
HC2H3O2(I) + O2(g) ---> H2O(I) + CO2(g) ΔH= -72.35 kJ
The beakers in the picture above are labeled according to the ionic solutions they contain. What metal or metals could replace copper in the copper(II) nitrate solution?
Explanation:
When a metal replaces another metal in solution, we say such a reaction has undergone a single displacement reaction.
In such a reaction, metal higher up in the activity series replaces another one due to their position.
To known the metal or metals that will replace the given copper, we need to reference the activity series of metals.
Every metal higher than copper in the series will displace copper from the solution.
So, there metals are: potassium, sodium, lithium, barium, strontium etc.
A small bubble rises from the bottom of a lake, where the temperature and pressure are 8°C and 6.4 atm, to the water's surface, where the temperature is 25°C and pressure is 1.0 atm. Calculate the final volume (in ml) of the bubble if its initial volume was 2.1 ml.
a. 0.070 ml
b. 21 ml
c. 14 ml
d. 42 ml
Answer:
b
Explanation:
The ____________________ two objects are from each other, the _____________ the force of gravity between them. fill in spaces
Answer:
Farther, lesser
Explanation:
The farther the two objects are from each other, the lesser the force of gravity between them.
The force of gravitational attraction between two bodies is inversely proportional to the distance between them.
This premised on the Newton's law of universal gravitation which states that "the gravitational force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distances between them".
So, the farther the distance, the lesser the gravitational attraction and vice versa.
Which phase do the chromosomes line up in the middle
Answer:
metaphase
Explanation:
the cells chromosomes line themselves in the middle of the cell through a type of cellular tug of war.
Answer:
metaphase
Explanation:
During metaphase, the cell's chromosomes align themselves in the middle of the cell through a type of cellular "tug of war." The chromosomes, which have been replicated and remain joined at a central point called the centromere, are called sister chromatids.
Why do we sometimes use roman numerals in naming ionic compounds?
We use roman numerals to indicate the oxidation state of metal atoms when naming compounds especially in the case of coordination compounds. It is a standard system of nomenclature.
What is oxidation state?Oxidation state of a species is the number electrons gained or lost. Oxidation state increases if electrons are lost from the atom and it will be decreased if electrons are gained.
For example, copper is in + 2 oxidation state in CuSO₄, thus it can be indicated as Cu(II). Copper can exists is +3 oxidation too. Thus the representation will be Cu (III).
All the transition metals like copper exhibit various oxidation state. So it is important to indicate in which oxidation state they are in a particular compound. In the compound Fe₂O₃, iron is in + oxidation state whereas in FeSO₄, it can be +2 . Thus it is important to note whether it is Fe (II) or Fe (III).
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The distance from the crest of one wave to the crest of the next wave.
A. microwaves
B. longitudinal
C. wavelength
D. electromagnetic
E. gamma rays
F. mechanical
Answer:
wavelength
Explanation:
_____ is the element from which iron is taken.
Carbon
Quartz
Hematite
1234567 sc: thatbitxh.lizzy
Answer:
okyay
Explanation:
lol
Answer:
12345678
Explanation:
i don't know so yea
Which type of bond will most likely be found in HBr given that the electronegativity of hydrogen is 2.20 and the electronegativity of bromine is 2.96?
an ionic bond
a metallic bond
a polar covalent bond
a nonpolar covalent bond
Answer:
C. A polar covalent bond
The most likely bond found in HBr is a polar covalent bond.
What kinds of bonds exist?Ionic bond : It is formed between metals and nonmetals and the difference in their electronegativities is higher than 1.7.Metallic bond : It is formed between metals with and the difference in their electronegativities is very small.Polar covalent bond : It is formed between nonmetals and the difference in their electronegativities is between 0.4 and 1.7.Nonpolar covalent bond: It is formed between nonmetals and the difference in their electronegativities is lower than 0.4.In HBr, both H and Br are nonmetals so the bond must be covalent. The difference in their electronegativities is:
ΔE = |EN(H)-EN(Br)| = |2.20-2.96| = 0.76
The most likely bond found in HBr is a polar covalent bond.
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Calculate the pH of the following?
a) 0.12 M NaNO2
b) 0.10 M CH3NH3Cl
c) .45 M NaOCl?
How many torr, atms, and psi is 303.9 kPa equal to?
Torr=
Atms=
Psi=
I'LL NAME YOU BRAINLIEST AND GIVE YOU 20 POINTS, IF YOU HELP ME SOLVE THIS PROBLEM!!!!! /^?^/ !!!
Answer:
2.99 atm
2279.43 torr
44.07 psi
Explanation:
Torr, atms and psi all units are units of pressure.
Conversion from KPa to atm:
1 KPa is equal to 0.00987 atm. To convert from KPa to atm we will multiply the given value with 0.00987 atm.
303.9 KPa × 0.00987 atm / 1 KPa
2.99 atm
Conversion from KPa to torr:
1 KPa is equal to the 7.5006 torr. To convert from KPa to torr we will multiply the KPa value by 7.5006.
303.9 KPa × 7.5006 torr/ 1 KPa
2279.43 torr
Conversion from KPa to psi:
psi is pound per square inch. 1 KPa is equal to the 0.1450 psi. To convert from KPa to psi we will multiply the KPa value by 0.1450 psi.
303.9 KPa × 0.1450 psi / 1 KPa
44.07 psi
balance the equation
____ NH4OH + ____ H3PO4 ____ (NH4)3PO4 + ____ H2O
Answer:
3NH4OH + H3PO4 -----> (NH4)3PO4 + 3H2O
Explanation:
L.H.S
3NH4OH + H3PO4
N = 3H = 18O = 7P = 1R.H.S
(NH4)3PO4 + 3H2O
N = 3H = 18O = 7P = 1Determine the formula for iron l oxide
What is the chemical formula for sodium sulfate
Answer:
Na2So4
Explanation:
Na is group 1, so has a charge of 1+
Sulphate’s formula is SO4 2-,
because sulphate has double the charge of Na, you need two Na’s to make it equal.
Therefore it’s Na2SO4
Which statement below is TRUE about COMPOUNDS? *
a) Compounds are made up of the same type of atoms.
b) Compounds are made up of only 1 atom.
d) Compounds are made up of different atoms stuck together.
d) Compounds can only contain 2 atoms.
How many atoms are there in 3.3 moles of strontium?
Explanation:
Multiply the moles Fe by 6.022×1023 atoms/mol
1) In the image below, determine the temperature in Fahrenheit.*
C 40
F
300
30
80
20
60
10
0
40
°F
Answer:
28.8889 or in simple terms 28.9 :) hope i helped
Explanation:
Answer:
28.8889 or in simple terms which I like to use is 28.9
The liquid inside the cell is called
Answer:
The cytoplasm
Explanation:
Cytoplasm is the gelatinous liquid that fills the inside of a cell. It is composed of water, salts, and various organic molecules. Some intracellular organelles, such the nucleus and mitochondria, are enclosed by membranes that separate them from the cytoplasm.
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What will be the mass of 9.95 liters of propane gas (C3H8) at STP?
Answer:
19.5g
Explanation:
Given parameters:
Volume of propane gas = 9.95L
Unknown:
Mass of propane gas = ?
Solution:
To solve this problem, find the number of moles first.
At STP;
22.4L of gas makes up 1 mole
9.95L of gas will have a [tex]\frac{9.95}{22.4}[/tex] = 0.44mole
So;
Mass of propane gas = number of moles x molar mass
Molar mass of propane = 3(12) + 8(1) = 44g/mol
Mass = 0.44 x 44 = 19.5g
Hydrazine, N2H4, and hydrogen, H2O2, have been used as rocket propellants. They react according to the equation:
H2O2 + N2H4 → N2 + H2O
a. How many moles of N2 are formed from 0.0250 moles of N2H4? (0.0250)
b. How many moles of H2O2 are required if 1.35 moles of H2O is to be produced? (0.675)
c. How many moles of H2O are formed if 1.87 moles of N2 is produced? (7.48)
Explanation:
The equation of the reaction is;
H2O2 + N2H4 → N2 + H2O
Upon balancing the reaction, we have;
N2H4 + 2H2O2 → N2 + 4H2O
a. How many moles of N2 are formed from 0.0250 moles of N2H4?
From the equation of the reaction;
1 mol of N2H4 produces 1 mol of N2
0.0250 mol of N2H4 would produce x mol of N2
1 = 1
0.0250 = x
x = 0.0250 * 1 / 1 = 0.0250 mol
b. How many moles of H2O2 are required if 1.35 moles of H2O is to be produced?
From the equation of the reaction;
2 mol of H2O2 produces 4 mol of H2O
x mol of H2O2 produces 1.35 mol of H2O
2 = 4
x = 1.35
x = 1.35 * 2 / 4 = 0.675 mol
c. How many moles of H2O are formed if 1.87 moles of N2 is produced?
The relationship between H2O produced and N2 is;
For every 1 mol of N2 produced, 4 mol of H2O is produced
1.87 mol of N2 produced, how many moles of H2O is produced?
1 = 4
1.87 = x
x = 1.87 * 4 / 1 = 7.48 mol
What is the charge of an electron?
A-negative
B-neutral
C-positive
D-none of these
What is the formula for displacement? *
1- Final position minus initial position
2- Relation to a reference point plus distance travelled
3- Distance divided by time
4- Speed times vector
Answer:
2 i think i am not very good at this lol
Explanation:
The units that acceleration use are distance/time^2 (in metric units).
The acceleration is the change of velocity over time, so
In another way, if the velocity is constant, the acceleration is zero, but if the velocity change over the time (as a car do when the red light change), the acceleration takes value!.
4. List if each of the following data is qualitative or quantitative:
a. ________________ Green
b. ________________ 5.7 grams
c. ________________ Large
d. ________________ 120 lbs
Explanation:
a. qualitative
b. quantitative
c. quantitative
d. quantitative
Hope this helps you.