Answer:
Explanation:
Convection
Cold air sinks
Hot air rises
Radiation
faster
better
poor
I think
WBCS are often called soldier of the body why
Answer:
White blood cells are cells of the system, which play a neighborhood in protecting the body against infectious diseases and foreign bodies. These cells flow with the blood throughout the body then scavenge and kill the parasites and foreign bodies. Hence, they are called soldiers of the body.
I hope it's helpful!
Sodium metal reacts with water to produce hydrogen gas according to the following equation:
2Na(s) + 2H2O(l)2NaOH(aq) + H2(g)
The product gas, H2, is collected over water at a temperature of 25 °C and a pressure of 759 mm Hg. If the wet H2 gas formed occupies a volume of 8.11 L, the number of grams of H2 formed is _______g. The vapor pressure of water is 23.8 mm Hg at 25 °C.
Answer:
0.648 g
Explanation:
Step 1: Write the balanced equation
2 Na(s) + 2 H₂O(l) ⇒ 2 NaOH(aq) + H₂(g)
Step 2: Calculate the partial pressure of H₂
The total pressure (P) is equal to the sum of the partial pressures of hydrogen and water vapor.
P = pH₂O + pH₂
pH₂ = P - pH₂O
pH₂ = 759 mmHg - 23.8 mmHg = 735 mmHg
Step 3: Convert "pH₂" to atm
We will use the conversion factor 1 atm = 760 mmHg.
735 mmHg × 1 atm/760 mmHg = 0.967 atm
Step 4: Convert "25°C" to K
We will use the following expression.
K = °C + 273.15 = 25°C + 273.15 = 298 K
Step 5: Calculate the moles of hydrogen (n) formed
We will use the ideal gas equation.
P × V = n × R × T
n = P × V/R × T
n = 0.967 atm × 8.11 L/(0.0821 atm.L/mol.K) × 298 K = 0.321 mol
Step 6: Calculate the mass corresponding to 0.321 moles of hydrogen
The molar mass of H₂ is 2.02 g/mol.
0.321 mol × 2.02 g/mol = 0.648 g
show the formation of oxygen molecule
Answer: H2o
Explanation:
because oxygen is in the air
Looking across period 4 of the periodic table, potassium (atomic number 19) is followed by calcium (atomic number 20), which is followed by scandium (atomic number 21). Which element should have the largest atomic radius?
Glycerophospholipids (phosphoglycerides) are components of cell membranes.
a. True
b. False
Answer:
The correct answer is a. True
Explanation:
The main components of cell membranes are lipids and proteins. Lipids are responsible to form the structural barrier with the surroundings. The general structure of the membrane is made up of phospholipids, which have a part of the molecule with affinity to other lipids, and another part with affinity to water. The most common and abundant phospholipids are glycerophospholipids.
Therefore, the sentence is true.
1. Write a balanced chemical equation, including physical state symbols, for the combustion of liquid dodecane into gaseous carbon dioxide and gaseous water.
2. Suppose 0.22 kg of dodecane are burned in air at a pressure of exactly and a temperature of 17.0°C. Calculate the volume of carbon dioxide gas that is produced. Round your answer to significant digits.
Answer: [tex]2C_{12}H_{26}(l)+37O_2(g)\rightarrow 24CO_2(g)+26H_2O(g)[/tex]
2. 369 L
Explanation:
1. Combustion is a chemical reaction in which hydrocarbons are burnt in the presence of oxygen to give carbon dioxide and water.
The balanced chemical reaction is:
[tex]2C_{12}H_{26}(l)+37O_2(g)\rightarrow 24CO_2(g)+26H_2O(g)[/tex]
2. To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{220g}{170.3g/mol}=1.29moles[/tex]
According to stoichiometry :
2 mole of dodecane produces = 24 moles of carbon dioxide
Thus 1.29 moles of dodecane produces = [tex]\frac{24}{2}\times 1.29=15.5 moles[/tex] of carbon dioxide
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1 atm
V = Volume of gas = ?
n = number of moles = 15.5
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]17^0C=(17+273)K=290K[/tex]
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{15.5\times 0.0821L atm/K mol\times 290K}{1atm}=369L[/tex]
Thus the volume of carbon dioxide gas that is produced is 369 L
¿The presence of which atmospheric condition will most likely result in clear skies in Binghamton, New York?
Answer:
Most Likely A High Pressure Center
Explanation:
is most likely high pressure Center because on a weather map over the southern western Pennsylvania there's mostly high pressure over there. The descending air diverges and spreads out from the center and their is a Coriolis effect which causes the Diverging air to rotate in a clockwise direction.
What is the skin's natural oil?
a. sweet
b. Melanin
c. sebum
d. vegetable oil
help
Answer:
C. Sebum
Explanation:
C. Sebum
Nitric oxide gas, NO(g), can be oxidized in air to
produce nitrogen dioxide gas, NO2(g):
2 NO(g) + O2(g) → 2 NO2(g)
Determine the enthalpy change for this reaction
using any of these thermochemical equations:
02(g) →20(g)
AH = +495 kJ
Hope this helps!!
Thank You!
Mixing hydrochloric acid (HCl) and aqueous calcium hydroxide produces water and aqueous Calcium Chloride. Write the complete and net ionic equations
Answer:
HCI+Ca(OH)2
Explanation:
25.0 mL of a 3.25 M solution is diluted to 450.0 mL. What is the concentration of the diluted solution?
Answer:
0.181 M
Explanation:
Begin by finding the total moles by using the volume and molarity given:
[tex]\frac{3.25 mol}{1000 mL} x \frac{25.0 mL}{1} = 0.08125 mol[/tex]
(Remember molarity is mol/L, which is equal to mol/1000 mL.)
Divide the moles by the volume after dilution:
[tex]\frac{0.08125 mol}{450.0 mL} x \frac{1000 mL}{1 L} = \frac{0.181 mol}{L} = 0.181 M[/tex]
The concentration of the diluted solution is 0.181 M.
True or false atoms are the smallest particle of an element that have that elements properties
Answer:false
Explanation:false
Answer:
true
Explanation:
hoping for the brainliest
Help please thank you
Answer:
It’s probably plants seed and raise crops for their food
Explanation:
Answer:
I would say b
Explanation:
A hunter would go out to hunt and gathers handle crops or find crops so b.
evaluate {(7.8)^2-(2.2^2
Answer:
56
Hope this helps :)
Food is taken in and broken down by the _______ system. The raw materials are then transported throughout the body by the _______ system.
A. nervous; skin
B. respiratory; circulatory
C. digestive; circulatory
D. digestive; skin
Answer:
C. digestive; circulatory
Explanation:
It is the correct answer..
Why might calcium also be called the calcium of citric acid
Calcium also be called the calcium of citric acid because calcium citrate malate contains the calcium salt of citric acid and malic acid.
What is citric acid?Citric acid is an organic compound with a chemical formula [tex]HOC(CO_2H)[/tex].
Calcium citrate malate is a water-soluble calcium supplement. It is the calcium salt of citric acid and malic acid with variable composition.
Hence, calcium is also called the calcium of citric acid.
Learn more about citric acid here:
https://brainly.com/question/11238674
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Antacids are used to treat acid reflux by neutralizing stomach acid, which is hydrochloric acid. Calcium carbonate, sodium bicarbonate and aluminum hydroxide are common main ingredients found in various brands of antacids. The brand Tums has calcium carbonate as the main ingredient to neutralize stomach acid. Write a balanced equation to show how Tums will neutralize stomach acid, and answer the following questions based on this reaction.
Answer: [tex]CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2[/tex]
Explanation:
Neutralization is a chemical reaction in which acid and base combine to form salt and water. Acids donate[tex]H^+[/tex] and bases donate [tex]OH^-[/tex] in water which combine to form water molecules.
The chemical reaction between calcium carbonate and hydrochloric acid forms calcium chloride , water and carbon dioxide.
The balanced chemical equation is:
[tex]CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2[/tex]
what is conductor?
give two examples.
Answer:
Conductor is any material tht allows he flow of electrons or electric current . Ex: Metals like iron and copper.
Hope im right!!
Answer:-
Examples of conductors include metals, aqueous solutions of salts (i.e., ionic compounds dissolved in water), graphite, and the human body. Examples of insulators include plastics, Styrofoam, paper, rubber, glass and dry air.Suppose that you are performing a titration on a monoprotic acid. Titration of this monoprotic acid required a volume of 0.1L of the base being used. If the same volume of a diprotic acid would instead have been used (same volume of a diprotic acid versus the originally used monoprotic acid), and if we assume furthermore that the concentration of the diprotic acid and the monoprotic acids are equal, how does the volume of base required to reach the endpoint for the diprotic acid compare to the volume of base required to reach the endpoint for the monoprotic acid?
A) More base is likely required to reach the endpoint for the diprotic acid than for the monoprotic acid under these conditionsB) Less base is likely required to reach the endpoint for the diprotic acid than for the monoprotic acid. C) Exactly the same amount of base is required for both monoprotic and diprotic acids under the situations described here.D) A completely different indicator will need to be used here.
Answer: A) More base is likely required to reach the endpoint for the diprotic acid than for the monoprotic acid under these conditions
Explanation:
The monoprotic acid (HA) has a valency of 1 and diprotic acid [tex](H_2A)[/tex] has a valency of 2.
As the concentration and volume of the diprotic acid and the monoprotic acids are equal.
The neutralization reaction for monoprotic acid is:
[tex]HA+BOH\rightarrow BA+H_2O[/tex]
The neutralization reaction for diprotic acid is:
[tex]H_2A+2BOH\rightarrow B_2A+2H_2O[/tex]
Thus more number of moles of base are required for neutralization of diprotic acid and thus the volume required will be more as concentration and volume of the diprotic acid and the monoprotic acids are equal.
sea stars have radial symmetry .what does this mean?
Answer: Echinoderms usually have five appendages (arms or rays), but there are some exceptions. Radial symmetry means that the body is a hub, like a bicycle wheel, and tentacles are spokes coming out of it (think of a starfish).
Explanation:
Answer:
uesssf
Explanation:
hnjhj
i need help with this please
Answer:
owa owa owa owa
Explanation:
owa owa owa owa owa owa owa
True or false water molecules are polymers
6 The final process in the formation of sedimentary rock is - A. cementation B. melting C.cooling
Answer:
A. cementation
Explanation:
( it deleted my answer)
Which item isn't a resource?
food
shelter
temperature
available mates
Answer:
temperature
Explanation:
hope this helps
g Imagine that you found a piece of carved wood that has been embedded in glacial ice. The mass of the wood is 50 grams, and 30% of the mass is carbon. The 14C/12C ratio of the wood was measured by mass spectrometry, and found to be 20 % of the 14C/12C ratio found in CO2 in modern air. You may assume that the half life of 14C is 5700 years. Which is the best estimate of the age of the wood
Answer:
13414 years
Explanation:
From;
0.693/ t1/2 = 2.303/t log No/N
t1/2 = half life of C-14
t = age of the sample
No= initial amount of C-14
N = present amount of C-14
From the question, N = 0.2 No
Hence;
0.693/5700 = 2.303/t log No/0.2No
1.2 * 10^-4 = 2.303/t log 1/0.2
1.2 * 10^-4 = 1.6097/t
t = 1.6097/1.2 * 10^-4
t = 13414 years
if you understand please help me x
Answer:
1. Percentage yield is 64.75%
2. Atom economy is 48.39%
Explanation:
1. Determination of the percentage yield
Experimental yield = 24.8 g
Theoretical yield = 38.3 g
Percentage yield =?
Percentage yield = Experimental yield /Theoretical yield × 100
Percentage yield = 24.8 / 38.3 × Percentage yield = 2480 / 38.3
Percentage yield = 64.75%
2. Determination of the atom economy.
The balanced equation for the reaction is given below:
6CO₂ + 6H₂O —> C₆H₁₂O₆ + 6O₂
Next, we shall determine the mass of CO₂, H₂O and C₆H₁₂O₆ from the balanced equation.
Molar mass of CO₂ = 12 + (16×2)
= 12 + 32
= 44 g/mol
Mass of CO₂ from the balanced equation = 6 × 44 = 264 g
Molar mass of H₂O = (2×1) + 16
= 2 + 16
= 18 g/mol
Mass of H₂O from balanced equation = 6 × 18 = 108 g
Molar mass of C₆H₁₂O₆ = (6×12) + (12×1) + (6×16)
= 72 + 12 + 96
= 180 g/mol
Mass of C₆H₁₂O₆ from the balanced equation = 1 × 180 = 180 g
Next, we shall determine the total mass of the reactants. This is illustrated below:
Mass of CO₂ = 264 g
Mass of H₂O = 108 g
Total mass of reactants =?
Total mass of reactant = Mass of CO₂ + Mass of H₂O
Total mass of reactant = 264 + 108
Total mass of reactant = 372 g
Finally, we shall determine the atom economy. This can be obtained as follow:
Mass of desire atom (C₆H₁₂O₆) = 180 g
Total mass of reactants = 372 g
Atom economy =.?
Atom economy = mass of desire atom / total mass of reactant × 100
Atom economy = 180/372 × 100
Atom economy = 48.39%
chemistry semester 2
Which of these objects are malleable? Check all that apply
Answer: Options 1,3,6
Explain why this crossing could result in white hedgehogs even though brown is dominant
Answer:
Because The white gene is the recessive gene and the brown gene is the dominant gene hence all the offspring being brown instead of white :)
Explanation:
Thank me later!
Which event is an example of sexual reproduction in plants?
A. Pine trees produce seeds in cones.
B. Mosses form spores in capsules.
C. A kalanchoe produces plantlets on its leaves.
D. A potato has buds that can grow into new stems.
Answer:
the correct answer to your question is b