Answer:I’ll ask my teacher
Explanation:
Match these items.
1. bring blood to the heart .veins
2. major artery bringing blood from the heart to the body .ventricle
3. doorways to the heart .aorta
4. measure of the rate of heart contractions .pulse
5. heart passageway to the arteries. valve
6. passage to the ventricle .atrium
Answer:
1- veins
2-aorta
3-valve
4-ventricles
5-atrium
Which of the following statements best describes a
mixture?
O A substance that contains two or more elements chemically joined
O A substance that contains two or more elements not chemically joined
O A substance that contains only one type of atom
O A substance that contains two or more compounds or elements that are
not chemically joined.
Mercury(II) oxide decomposes to form mercury and oxygen, like this:
2Hg (l) + O2 (g) → 2HgO (s)
At a certain temperature, a chemist finds that a reaction vessel containing a mixture of mercury(II) oxide, mercury, and oxygen at equilibrium has the following composition:
compound amount
Hg 14.7g
O2 13.4g
HgO 17.8g
Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits. Clears your work. Undoes your last action. Provides information about entering answers.
Solution :
For the reaction given :
[tex]$\text{2Hg}_{(l)}+\text{O}_2_{(g)} \rightarrow \text{2HgO}_{(s)}$[/tex]
Thus we know that the equilibrium constant [tex]$K_c$[/tex] contains aqueous an dgas species only.
∴ [tex]$K_c=\frac{1}{[O_2]}$[/tex] ............(1)
Now at the equilibrium, an amount of the 13.4 g of oxygen was found in the vessel of 6.9 liters. For determining the concentration of the oxygen gas, we use :
[tex]$[O_2]= \frac{n_{O_2}}{V_{soln}}$[/tex] ................... (2)
Here, [tex]$n_{O_2}$[/tex] = no. of moles of oxygen gas (mol)
[tex]$V_{soln}$[/tex] = volume of solution (L)
Therefore the number of moles of the oxygen gas is calculated by directly using the molecular weight (31.9988 g/mol) as the conversion factor.
∴ [tex]$n_{O_2}= 13.4 \ g \times \frac{\text{1 mol}}{31.9988 \ g}$[/tex]
= 0.418 mol
Now substituting the known values in (2), we can find the equilibrium concentration of the oxygen gas :
[tex]$[O_2] =\frac{0.418 \ \text{mol}}{6.9 \ \text{L}}$[/tex]
= 0.0605 M
Therefore substituting the result in (1), the equilibrium constant for the reaction is :
[tex]$K_c=\frac{1}{0.0605}$[/tex]
= 16.52
I NEED AWNSER ASAP What forms as a result of the wind's frictional force on water?
deep sea currents that move in a path opposite to the wind currents
surface currents that move in a path similar to the wind currents
surface currents that move in a path opposite to the wind currents
deep sea currents that move in a path similar to the wind currents (the sub is science)
Answer:
2 no. is the answer surface currents that move in a path opposite to the wind currents
Answer:
no.2 is the answer of your question
Question 2 (1 point)
Which of the following does NOT involve a chemical reaction?
Fallen leaves decay in a compost pile.
Leaves change color in the fall.
O A fire burns a pile of fallen leaves.
A pond freezes over in the winter.
Answer:
D. A pond freezing over is not a chemical reaction, it is a physical reaction.
The smallest arteries in your body are called _____. arterioles capillaries veins bronchioles
Answer: arterioles
Explanation:
The percent composition by mass of nitrogen in NH OH (gram-formula mass = 35 grams/mole) is equal to
Answer:
the percentage composition of mass of nitrogen in NH OH is 42.86 %
PLLLzzzzzzzz helpppp Which is correct lab safety? A) Rodney wafted the fumes produced during the reaction toward his nose. B) Andrew heated the test tube towards himself in order to better observe the reaction. Eliminate C) Kadie was aware of the lab procedures that day so she began the lab before the rest of the class to be sure she would finish. D) Suzanne did not use all of the sulfuric acid she poured out for the experiment, so she returned the remainder to the stock bottle.
Answer:
A
Explanation:
can i get brainliest pls
A force of 10 N pulls an object to the right, and a force of 7 N pulls to the left, what is the net force
Answer:
2 N
Explanation:
Green plants use light from the Sun to drive photosynthesis, a chemical reaction in which liquid water and carbon dioxide gas form aqueous glucose C6H12O6 and oxygen O2 gas. Calculate the moles of oxygen produced by the reaction of 0.800mol of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to 3 significant digits.
Answer:
0.800 mol of O2
Explanation:
Calculate the moles of oxygen produced by the reaction of 0.800mol of carbon dioxide.
The balanced equation for the reaction is given as;
6CO2 + 6H2O → C6H12O6 + 6O2
From the reaction;
6 mol of CO2 produces 6 mol of O2
0.0800 mol of CO2 would produce x mol of O2
6 = 6
0.0800 = x
Solving for x;
x = 6 * 0.800 / 6
x = 0.800 mol
True or False: The specialized cells in a UNICELLULAR organism perform
specialized jobs.
Your answer
Answer:
True
Explanation:
Laura can use a toy car to demonstrate the force of gravity by doing which of these?
Letting the toy car roll down a ramp
Placing the toy car on the floor
Lifting the toy car onto a shelf
Pushing the toy car across a table
Answer:
letting the car fall down the ramp i got that right.
Explanation:
What is the molar mass of AIC13?
help please will give brainly if right
Answer:
B and D
Explanation:
Because its adaptions they need to survive in the cold.
A granulated cylinder was filled to 30.0 mL with liquid. An unknown metal cylinder having a mass of 60.27 g was submerged in the liquid. The final volume of the liquid level was 45.2 mL.
Answer:
Explanation:
A graduated cylinder was filled to 30.0 mL with a liquid. An unknown metal cylinder having a mass of 60.27 g was submerged in the in the liquid. The final volume of the liquid level was 45.2 mL.
a. Calculate the density of the unknown metal cylinder.
b. The density of the liquid is 0.899 g/mL. What is the mass of the liquid in the graduated cylinder?
6CuNO3 + Al2(SO4)3 → 3Cu2SO4 + 2Al(NO3)3
Molar mass of CuNO3 125.56 g/mol
Molar mass of Al(NO3)3 213.01 g/mol
How many grams of copper (I) nitrate (CuNO3) are required to produce 44.0 grams of aluminum nitrate (Al(NO3)3)?
Answer:
77.81 g of CuNO₃
Explanation:
6 CuNO₃ + Al₂(SO₄)₃ ⇒ 3 Cu₂SO₄ + 2 Al(NO₃)₃
This is your chemical equation. We will need this information for converting from Al(NO₃)₃ to CuNO₃.
First, convert grams of Al(NO₃)₃ into moles using the molar mass.
[tex]44.0g*\frac{mol}{213.01g} = 0.2065mol[/tex]
Next, convert moles of Al(NO₃)₃ to moles of CuNO₃. You can do this by using the stoichiometry (the numbers in front of the compounds). For every 6 moles of CuNO₃, you will get 2 moles of Al(NO₃)₃, causing the ratio of CuNO₃ to Al(NO₃)₃ to be 6:2.
[tex]0.2065mol*\frac{6}{2} =0.6197mol[/tex]
Now that you moles of CuNO₃, convert this to grams using its molar mass.
[tex]0.6197 mol * \frac{125.56g}{mol} =77.81 g[/tex]
You will need 77.81 grams of CuNO₃ to produce 44.0 grams of Al(NO₃)₃.
Which of the following is the correct decreasing order of hydrogen ions concentrations?
Answer: A> B> C > D> E
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
[tex]pH=-\log [H^+][/tex]
a) Solution A: pH =2
[tex][H^+]=10^{-2}[/tex]
b) Solution B: pH =5
[tex][H^+]=10^{-5}[/tex]
c) Solution C: pH = 7
[tex][H^+]=10^{-7}[/tex]
d) Solution D: pH = 8
[tex][H^+]=10^{-8}[/tex]
e) Solution E: pH =13
[tex][H^+]=10^{-13}[/tex]
Thus the decreasing order of hydrogen ion concentration is A> B> C > D> E
AWNSER FAST PLEASE
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(awnsers H²O -> (awnsers H² -> (awnsers O²
awnser for all drop-down menus 1,2, or 3
Answer: The coefficients are 2, 2 and 1.
Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants.
The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for the given reaction is:
2H2o➡️2h2+o2
need help whoever answers will be awarded branliest answer
Answer:
1.used to seperate solids from liquids, and is a act of pouring a mixture onto a membrane this allows the passage of liquid and results in the collection of a solid
2. the solution would passed through without losing and solids
3 would allow them to dry or on further hearing decompose
Explanation:
a change of state does not affect an object's what.
Answer:
Mass
Explanation:
Which example indicates that a chemical change has occurred? *
1 point
A. When two aqueous solutions are mixed, a precipitate is formed.
B. As ammonium nitrate dissolves in water causes the temperature to decrease.
C. Alcohol evaporates when left in an open container.
D. Water is added to blue copper(II) chloride solution. The resulting mixture if lighter blue in color.
Answer:
A. When two aqueous solutions are mixed, a precipitate is formed.
Explanation:
The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.
The other three answer choices are indicative of physical changes (temperature change, phase change, color change).
When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.
Hence, option A is correct answer.
What is Chemical change ?Chemical change are those changes in which substance changes chemical composition. These changes are permanent changes. In chemical change new substances formed and in chemical change substances can not get back into its original form. It is irreversible change.
What is Physical change ?Physical changes are those changes in which substance changes physical properties only. Properties like temperature, pressure, shape, color, size, state (solid, liquid and gas). These changes are temporary in nature. In physical change no new substances formed. It is reversible change.
Now, check all the options one by one:
Option (A): When two aqueous solutions are mixed, a precipitate is formed is a chemical change. Since precipitation indicate a chemical reaction (that is double displacement reaction).
Option (B): As ammonium nitrate dissolved in water causes the temperature to decrease is a physical change because heat energy is absorbed here and it is a endothermic reaction.
Option (C): Alcohol evaporates when left in an open container is a physical change because evaporation is a physical change as it changes the state from liquid state to gas state.
Option (D): Water is added to blue copper (II) chloride solution. The resulting mixture if lighter blue in color is a physical change as properties like change in color is physical change.
Thus, from above conclusion we can say that When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.
Hence, option A is correct answer.
Learn more about physical and chemical change here: https://brainly.com/question/17166994
#SPJ2
what grade percentage is developing, proficient, exceeding, and emerging?
Answer:
Grade A is the best percentage that is developing, proficient, exceeding, and emerging
How many moles are in 2.5L of 1.75 M Na2CO3
Answer:
4.375 moles Na2CO3
Explanation:
Formula for molarity is;
M = n/V
Where;
M is molarity
n is number of moles
V is volume
Making n the subject we have;
n = VM
We are given;
M = 1.75 M
V = 2.5 L
Thus;
n = 2.5 × 1.75
n = 4.375 moles Na2CO3
Answer:
4.375 moles Na2CO3
Explanation:
Have a great day
Which statement best describes the energy in the food web? A. The amount of energy available at level B depends on the amount of energy available at level C. B. The amount of energy available at level A depends on the energy provided from an abiotic source. C. The amount of energy available at level C is greater that the amount of energy available ate level A. D. The amount of energy available at level B is transferred to level A
Answer:
The amount of energy available at level A depend on energy provided from an a biotic source
what energy is walking?
A. light energy
B. sound energy
C. Thermal energy
D. Mechanical energy
E. electrical energy
Answer:
Mechanical
Explanation:
a furnace is thermal energy
A. True
B. False
Answer: true
Explanation:
Thermal efficiency of process heating equipment
hi, if your looking for extra points (50+) and brainiest here is ur chance, answer this question correctly plz
Answer:
Answer is B
Explanation:
It's not A because we're boiling only water.
It's not C because the last dot for 2 cups ends at 70 min while the last dot for 4 cups ends at 90 min.
It's not D because water boils at around 100 C, as shown in the graph. The highest dot for both 2 cups and 4 cups were about the same near 100 C.
The graph shows that 4 cups of water is able to retain heat more (higher heat capacity), so it takes more time for water to cool down than 2 cups of water.
Please help me thanks
Answer:
your finger becomes negatively charged
Explanation:
hope it helps. follow me
How many grams of AlCl3 will be produced if 3.85 moles of Al react? Al + ___Cl2 → ___AlCl3
Answer:
513.975g
Explanation:
I'm assuming that the question has Aluminium and Chlorine as the question is not clear.
1. Balance the equation
2 Al + 3 Cl2 → 2AlCl3
2. Use the mole = mass/mr equation and molar ratio to find the mass of AlCl3
133.5 x 3.85 = 513.975g
Which part of a calcium atom in the ground state is represented by the dots in its Lewis electron-dot diagram?
Answer:
There are two dots are present on the left side of calcium atom which represents the unpaired electrons present in the outermost shell. This structure is presented by Lewis in order to show the number of unpaired electrons in the atom.
Explanation: