Answer:
the answer is B.
Explanation:
The heat is created
show the formation of oxygen molecule
Answer: H2o
Explanation:
because oxygen is in the air
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..
True or false water molecules are polymers
When sodium chloride and metallic sodium are
each dissolved in water A. both processes are
exothermic B. both processes are endothermic
C. the dissolution of metallic sodium is endothermic
D. the dissolution of metallic sodium is exothermic
E. the dissolution of sodium chloride is explosive
Answer:
B
Explanation:
don't try to do that at home
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.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:
chemistry semester 2
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!
I need help please
I got stuck and now confused
Answer: Triels, Tetrels, Pnictogens and Chalcogens
Explanation:
Between the Transition metals and the Halogens lies Groups 13, 14, 15 and 16.
Group 13 are also known as Triels and consist of elements like Boron and Aluminium.
Next up is Group 14 also known as the Tetrals and they consist of elements like Carbon, Silicon and Tin.
The Group 15 elements are known as Phictogens and consist of Nitrogen, Phosphorus and Arsenic.
Finally we have the Chalcogens or Group 16 elements such as oxygen, Sulfur and Selenium.
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.
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)
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!
How does a duckling become a bigger and stronger adult duck?
A. Body repair
B. Warmth
C. Growth
D. Motion
Answer:The correct answer is C.
Explanation: I had it on a quiz
Answer: the answer is C growth
Explanation: body repair, motion and warmth are not the answer the reason why is because body repair is when the body repairs it’s self if it’s hurt and motion is when animals use the energy from the food they eat to move and warmth helps animals to get warm so they don’t get to cold so the answer would be growth .
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:
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Explanation:
hnjhj
Which item isn't a resource?
food
shelter
temperature
available mates
Answer:
temperature
Explanation:
hope this helps
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
A vaccine used against an infectious disease may contain
Answer:
Vaccines include a variety of ingredients including antigens, stabilizers, adjuvants, antibiotics, and preservatives. They may also contain residual by-products from the production process.
Which of the following processes is endothermic?
Any combustion reaction
Bonds being made in the products
Bonds being broken in the reactants
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
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?
A sample of hydrogen gas occupies
1.0 L at 760 torr in a balloon. If the
temperature is kept constant, which
expression represents the volume of
hydrogen gas in liters when the
pressure is raised to 860 torr?
A 860 + 760
B 860 – 760
C 860 / 760
D 760 / 860
When the pressure of a sample of hydrogen gas increases from 760 torr to 860 torr, the expression D 760 / 860 represents the volume of hydrogen gas in liters.
What does Boyle's law state?Boyle's law is a law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature.
A sample of hydrogen gas occupies 1.0 L at 760 torr in a balloon. We can calculate the volume when the pressure is increased to 860 torr using Boyle's law.
P₁ × V₁ = P₂ × V₂
V₂ = (P₁/P₂) × V₁
V₂ = (760 torr/860 torr) × 1.0 L = 0.88 L
where,
P₁ and V₁ are the initial pressure and volume.P₂ and V₂ are the final pressure and volume.When the pressure of a sample of hydrogen gas increases from 760 torr to 860 torr, the expression D 760 / 860 represents the volume of hydrogen gas in liters.
Learn more about Boyle's law here: https://brainly.com/question/469270
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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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.
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
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]
¿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.
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%
35 points plz be fr will mark brainliest
Answer:
6. solar eclipsis
7. drive less fuel efficient vehicles
Explanation:
these are the only questions i get but i still hope this helps :)
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