Answer:
c. the amount of fossil fuels being burned increased
Explanation:
Carbon dioxide gas concentration increased over the time due to burning of fossil fuels increased. Fossil fuels are organic compounds which releases carbondioxide gas as a result of burning of fossil fuels in the engines of vehicles and industries. With the passage of time, number of vehicles increases in the world which needs more fossil fuels and due to burning of that fossil fuels, more carbondioxide gas is released.
Carbon burns in the presence of oxygen to give carbon dioxide. Which chemical equation describes this reaction?
ОА. .
carbon + oxygen + carbon dioxide
ОВ.
carbon + oxygen carbon dioxide
Ос. .
carbon dioxide carbon + oxygen
OD carbon dioxide + carbon - Oxygen
Answer:
(carbon dioxide → carbon + oxygen. (carbon dioxide + carbon → oxygen.
Explanation:
I'm not really sure if this is the answer
define blood circulation brefly
Answer:
blood circulation The circulation of blood refers to its continual flow from the heart, through branching arteries, to reach and traverse the microscopic vessels in all parts of the body, reconverging in the veins and returning to the heart, to flow thence through the lungs and back to the heart to start the circuit.
That is the answer. Your welcome
Which of the following can be used to indicate which direction heat transfer will flow between two
objects?
A. Cold
B. Heat
C. Temperature
D. Potential energy
Answer:
Its temperature
Explanation:
if the cold air wants to move to the hot air, then that means its trying toequal out t=both the temperatures. meaning that the cold air will get hotter and the hot were ill get colder.
Temperature can be used to indicate which direction heat transfer will flow between two objects. The correct option is C.
What is temperature?Temperature is the measurement entity of the hotness and coldness of any object or body. Its SI unit is kelvin or Celsius. The heat always transfers from the hot body to the cold body.
The heat is always transferred from high temperature to cold temperature. Heat is warmness that is caused by the thermal energy of the body when kinetic energy or potential energy is converted into thermal energy.
In a closed system, the energy is transferred by the means of heat and work. Otherwise, a closed system saves energy. The energy is transferred always within the same boundaries.
Thus, the correct option is C. Temperature.
To learn more about temperature, refer to the link:
https://brainly.com/question/15799226
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write a balenced chemical equation for the reaction: include abbreviation for the physical states-
A solution of magnesium bromide reacts with a solution of ammonium phosphate to form aqueous ammonium bromide and solid magnesium phosphate
Answer:
MgBr(aq) + (NH4)3PO4(aq) -------> NH4Br(aq) + Mg3(PO4)2(s)
Explanation:
4. Which of the following elements should be the best conductor of electric current?
Aluminum
Nitrogen
Helium
Phosphorus
Answer:
Aluminium
Explanation:
Answer:
aluminum because all the other three are not metals or conductors
Explanation:
The reason for an opals characteristic flash is because the sphere of silica are mixed with a small amount of what ? A.) Magma B.) Hydrogen C.) Methane D.) Water
Answer:Silica content influences magma behavior-____magmas have high silica content, are viscous (thick), and erupt at a lower temperature-____magmas have much lower silica content, more fluidlike behavior, and erupt at a higher temperature
Explanation:
when you throw a ball your hand applies ____ to the ball.
1. friction
2. force
3. normal force
4. inertia
5. second law of motion
6. first law of motion
7. acceleration
Answer:
2.force
Explanation:
How have government and businesses impacted energy efficiency?
Answer:
Government programs aim to increase incentives for consumers and producers to move toward energy efficiency.
Explanation:
Government programs aim to increase incentives for consumers and producers to move toward energy efficiency.
Please help me thanks so much?!?!?.:;)))) I will mark you:))
Answer:
D)
Explanation:
Answer:
the last one
Explanation:
Questions
What is the main point of the passage?
Ultraviolet rays can cause chemical reactions.
Van Gogh was the most famous painter of the Impressionist era.
Art conservationists can always restore art.
Artists' paints can eventually damage the canvasses.
201A
Based on the complete text, it is clear to see that the main point of the passage is A. Ultraviolet rays can cause chemical reactions.
What is a Central Idea?This refers to the theme of a text that is used in order to show the message that an author wants to convey in a given text that he wants his readers to understand and grasp.
Hence, we can see that from the complete text which can be found on the official website of BBC news site, the story is told about the ultraviolet rays that were found to cause chemical reactions and discolored some parts of the paintings by Vincent Van Gogh,
This is further explained as the bright yellows in the paintings chemically reacted and thus turned into brown color and this shows that option A is the correct answer that shows the central idea or main point of the text.
Read more about central ideas here:
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Calculate the following:
1. Mass of 4.3x10-3 mol of lead
2. Mass of 3.8x1022 antimony atoms
3. Number of atoms in 15.5 kg of tungsten
Answer:
1) Mass = 890.96 g
2) Mass = 7.67 g
3) 507.65 ×10²³ atoms
Explanation:
1) Given data:
Number of moles of lead = 4.3×10⁻³ mol
Mass of lead = ?
Solution:
Mass = number of moles × molar mass
Molar mass of lead = 207.2 g/mol
by putting values,
Mass = 4.3×10⁻³ mol × 207.2 g/mol
Mass = 890.96 g
2) Given data:
Number of atoms of antimony = 3.8×10²² atoms
Mass of antimony = ?
Solution:
1 mole contain 6.022 ×10²³ atoms
3.8×10²² atoms × 1 mol / 6.022 ×10²³ atoms
0.63×10⁻¹ mol
0.063 mol
Mass:
Mass = number of moles × molar mass
Molar mass of lead = 121.76 g/mol
Mass = 0.063 mol × 121.76 g/mol
Mass = 7.67 g
3) Given data:
Mass of tungsten = 15.5 Kg (15.5 kg × 1000 g/ 1kg = 15500 g)
Number of atoms = ?
Solution:
Number of moles of tungsten:
Number of moles = mass/molar mass
Number of moles = 15500 g / 183.84 g/mol
Number of moles = 84.3 mol
1 mole contain 6.022 ×10²³ atoms
84.3 mol × 6.022 ×10²³ atoms / 1mol
507.65 ×10²³ atoms
Ann dissolves four tablespoons of salt in a bowl of water. She notices that the water has become salty. Ann then keeps
the bowl out in the sun for along time. The water in the bowl evaporates, leaving crystals of salt behind in the bowl.
What kinds of change(s) have happened?
1)The salt dissolving is a physical change and the evaporation of water is a chemical change.
2)Both the salt dissolving and the evaporation of water are physical changes.
3)The salt dissolving is a chemical change, and the evaporation of water is a physical change.
4)Both the salt dissolving and the evaporation of water are chemical changes
Answer:
2)Both the salt dissolving and the evaporation of water are physical changes.
Explanation:
The two kinds of changes that has occurred are both physical changes.
Dissolution of a solute such as salt in water and evaporation of water from a solution are physical changes.
A physical change is one in which the physical property of matter is altered. Particularly the state and the form.
In many of these cases, the change is easily reversible.
Since this change is reversible in that we were able to collect the salt back, this is a physical change.
IS IT B, C, OR D
PLZ HELP AND DONT BE WRONG
Answer:
probably c i strongly agree with c
Explanation:
Answer:
I'm really not sure. my guess is the other person is probably right
In a synthesis reaction, the elements Fe and S might react to form which of the following?
A
H_2
2
O
B
FeS
C
Na and Cl
D
All of the above
Answer:
A
Explanation:
thanks for the points
Answer: it B
Explanation: i just took the test
A solution is prepare using 45.2 g of an unknown (nonelectrolyte) dissolved in 476.4 g of water. The freezing point depression
of the solution compared to water is measured to be 1.87°C. What is the molar mass of the unknown (in g/mol)?
Some possibly useful constants for water are K= 1.86°C/m and Kb = 0.512°C/m.
Enter your value using three significant figures.
Answer:
94.4g/mol is molar mass of the unknown
Explanation:
Based on the freezing point depression equation:
ΔT = Kf*m*i
Where ΔT is the depression in freezing point (1.87°C)
Kf is freezing point depression constant of water (1.86°Ckg/mol)
And i is Van't Hoff factor (1 for nonelectrolyte solutes)
Replacing:
1.87°C = 1.86°CKg/mol*m*i
1.005mol/kg solvent = m
Using the mass of the solvent we can find the oles of the nonelectrolyte:
1.005mol/kg solvent * 0.4764kg = 0.479moles
Molar mass is defined as the ratio between mass of a substance in grams and moles, that is:
45.2g / 0.479mol =
94.4g/mol is molar mass of the unknownIf we place 15 moles of NaN3, how many
grams of NaN3 do you have before the
reaction?
Answer:
25.8 g C6H12O6
Explanation:
The density of gold is 19.3 g/cm³. Which of the following shows the mass of a gold bar that is 4.50 cm × 8.00 cm × 20.00 cm?
Answer:
13896g
Explanation:
volume = 4.50×8.00×20.00 = 720 cm³
mass = density × volume
mass= 19.3 × 720 = 13896g
were do baby's come from
Answer:
Their moms and dads. ;)
Explanation:
Identify the type of reaction: H2CO3 → H20 + CO2
Answer: In the reaction carbonic acid and decomposes form's a water and carbon dioxide gas. Hence this is the an example of a decomposition reaction.
Explanation:
Hydrobromic acid dissolves solid iron according to the following reaction:
Fe(s)+2HBr(aq)→FeBr2(aq)+H2(g)
What mass of HBr (in g) would you need to dissolve a 2.8-g pure iron bar on a padlock?
What mass of H2 would be produced by the complete reaction of the iron bar?
Answer:
8.1g
0.1g
Explanation:
The reaction expression is given as:
Fe + 2HBr → FeBr₂ + H₂
Mass of pure iron given = 2.8g
A. Mass of HBr needed to dissolve a padlock of the mass;
To solve this problem, we need to use the mole concept.
Convert mass of the known iron to the number of moles.
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass = 56g/mol
Number of moles of iron = [tex]\frac{2.8}{56}[/tex] = 0.05mole
1 mole of Fe will react with 2 mole of HBr
0.05mole of Fe will react with 0.05 x 2 = 0.1mole of HBr
Mass of HBr = number of moles x molar mass
Molar mass of HBr = 1 + 80 = 81g/mol
Mass of HBr = 0.1 x 81 = 8.1g
B. What mass of H2 would be produced by the complete reaction of the iron bar
Since:
1 mole of Fe will produce 2 mole of hydrogen gas
0.05mole of Fe will produce 2 x 0.05mole = 0.1mole of hydrogen gas
Mass of hydrogen gas = number of moles x molar mass
= 0.1 x 1
= 0.1g
Plzzzzzzzz helpppppppppp
Answer:
true
Explanation:
They explained it in the answer
DEFINITION: ABILITY OF A SUBSTANCE TO BE DISSOLVED
Answer:
Solubility
Explanation:
If its not that the answer is Dissolvable.... you didn't give a word bank.
:))))))))))
Given that the mass number for carbon is 13, how many protons and how many neutrons does the isotope contain?
Answer:
6 protons
7 neutrons
protons is also the atomic number... and carbon is 6 on the periodic table. then just subtract the atomic number from the mass number.... then you get the number of neutrons
13-6= 7
Explanation:
A student needs to run 3.2
km to get to school. If the student can run 5.5
mi/hr , how many hours will it take them to get to school?
Answer:
Hope this helps.
Explanation:
Convert from miles to kilometers (rounded to 2 decimals):
5.5 mi/h * 1.609 = 8.86 km/h
The student arrives at school in:
8.86 km ------------- 1 h
3.2 km ---------------- x
x = 3.2 * 1 / 8.86
x = 0.3611 hours
A student titrates an unknown amount of potassium hydrogen phthalate (KHC8H4O4, abbreviated as KHP) with 21.30 mL of a 0.1161 M NaOH solution. KHP (molar mass
Answer:
0.5050g of KHP were titrated
Explanation:
... (molar mass = 204.22 g/mol) has one acidic hydrogen. What mass of KHP was titrated (reacted completely) by the sodium hydroxide solution?
The KHP is a salt used as standard to determine concentrations of bases as NaOH solutions. The reaction that occurs is:
KHP + NaOH → KP⁻Na⁺ + H₂O
Only 1 hydrogen is acidic. Only 1 hydrogen reacts with NaOH
In the reaction you can see that 1 mole of NaOH reacts per mole of KHP
To find mass of KHP we need to determine its moles finding moles of NaOH (The moles of KHP required to reach endpoint = Moles of NaOH added):
Moles NaOH:
21.30mL = 0.02130L * (0.1161mol / L) = 0.002473 moles of NaOH = Moles KPH
With mass of KHP and its molar mass we can solve the mass of KHP:
0.002473 moles of KHP * (204.22g/mol) =
0.5050g of KHP were titratedA flammable material is burning.
EXO
ENDO
A student investigated how much solid was dissolved in sea water.
The student:
1. Measured the mass of an empty evaporating basin.
2. Measured 50 cm3 of sea water and poured it into the evaporating basin.
3. Heated the evaporating basin gently until all of the water had evaporated.
4. Measured the mass of the evaporating basin containing the solid residue.
5. Reheated the evaporating basin and solid residue.
6. Measured the mass of the evaporating basin and solid residue.
7. Repeated steps 5 and 6 until the mass was constant.
Name two different pieces of apparatus that would be suitable for measuring:
• The mass of the evaporating basin
• 50 cm3 of sea water
Equipment to measure the mass of the evaporating basin_______________________
Equipment to measure 50 cm3 of sea water ________________________________
Answer:
weighing balance/analytical balance
Graduated cylinder/buret
Explanation:
The mass of the evaporating basin could be measured using a weighing balance or an analytical balance. Both are classified as weighing scales but the analytical balance can measure the mass of objects up to 4 decimal places, thus, providing better accuracy in measurement than ordinary weighing balance that can only measure up to 2 decimal places.
In order to measure 50 cm3 of the sea water, a graduated cylinder or a buret can be used. Both equipment can measure up to the same decimal places and, thus, have virtually the same accuracy.
At a given set of conditions 241.8 kJ of heat is released when one mole of H2O forms from its elements. Under the same conditions 285.8 KJ is released when one mole of H2O is formed from its elements. Find Delta h of the vaporization of water at these conditions
Answer:
44Kj
Explanation:
These are the equations for the reaction described in the question,
Vaporization which can be defined as transition of substance from liquid phase to vapor
H2(g)+ 1/2 O2(g) ------>H2O(g). Δ H
-241.8kj -------eqn(1)
H2(g)+ 1/2 O2(g) ------>H2O(l).
Δ H =285.8kj ---------eqn(2)
But from the second equation we can see that it moves from gas to liquid, we we rewrite the equation for vaporization of water as
H2O(l) ------>>H2O(g)---------------eqn(3)
But the equation from eqn(2) the eqn does go with vaporization so we can re- write as
H2O ------> H2(g)+ 1/2 O2(g)
Δ H= 285.8kj ---------------eqn(4)
To find Delta h of the vaporization of water at these conditions, we sum up eqn(1) and eqn(4)
Δ H=285.8kj +(-241.8kj)= 44kj
At what temperature can 60g of CaCl2 be dissolved in 100g of water?
how does mixture relate to life
Answer:
For example, when we bake a cake, it's a result of a mixture of eggs, flour, sugar, and other ingredients. Any time two or more items are combined, a mixture is formed. Sometimes, the different parts of a mixture can be separated into individual entities. Other times, they're married for as long as they exist.
Explanation:
