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
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 .
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?
True or false water molecules are polymers
show the formation of oxygen molecule
Answer: H2o
Explanation:
because oxygen is in the 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.
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 atoms are the smallest particle of an element that have that elements properties
Answer:false
Explanation:false
Answer:
true
Explanation:
hoping for the brainliest
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]
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
What properties makes it possible for substances to be separated using crystallisation
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)
1. Your friend has a balloon that can hold a volume of 5 L. If she added a 3 mol of CO2 gas at a pressure of 0.90 atm, what is the temperature of the balloon?
Answer:
I don't understand your question
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!
Why is it that the higher the molecular mass of the alkane, the higher the boiling point? Refer to intermolecuar forces and energy.
Answer:
Higher melting and boiling points signify stronger noncovalent intermolecular forces. Consider the boiling points of increasingly larger hydrocarbons. More carbons means a greater surface area possible for hydrophobic interaction, and thus higher boiling points.
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:
What is the solubility of 80 grams of magnesium chloride (MgCl2) dissolved into 150 cm3 of water?
A. 533.33g/dm3
B. 12g/dm3
C. 12000g/dm3
D. 1.88g/dm3
Answer:
A
Explanation:
In which of the following compounds does iron have the lowest oxidation number?
A. All are equal
B. Fe(OH)2
C. Fe(OH)3
D. FeOH
Answer:
C is the Answer
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Compounds are formed by the same or the different molecules of the elements. Iron has the lowest oxidation number in FeOH. Thus, option D is correct.
What is the oxidation number?The oxidation number is the total gain or loss of the electrons by the atom to form a chemical bond with another atom in a molecule or a compound.
The oxidation state in a neutral compound adds up to zero. The oxidation number of oxygen is -2, and that of hydrogen a monoatomic ion is always +1.
Oxidation states are calculated as,
Fe(OH)₂:
X + 2 (-2 +1 ) = 0
X -2 = 0
X = +2
Fe(OH)₃:
X + 3 (-2 +1 ) = 0
X - 3 = 0
X = + 3
FeOH:
X -2 + 1 = 0
X - 1 = 0
X = +1
Therefore, iron has the lowest oxidation number in FeOH.
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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.
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.
If 20.0 g NaOH reacts with 30.0 g of H2SO4 how much Na2SO4 is produced?
Given: 2NaOH(aq) + H2SO4(aq) | Na2SO4(aq) + 2H2O(l)
Answer:
10g
Explanation:
find the limiting agent first
using mole ratio
2 moles of NAOH reacts with 2 moles of H2SO4
then 20g of NAOH require 20g of H2SO4
USING mole ratio on the limiting agent and product
2moles of NAOH produces 1 mole of NA2SO4
THEN
20g of NAOH will produce X
THEN solve for X
X =10g
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.
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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.
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
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Question 24 (1 point)
To change 0.800 moles of liquid zinc to gaseous zinc, the amount of thermal energy required is
kj.
Ą Enter your three-digit answer.
Determine the amino acid sequence of a polypeptide from the following data:
Complete hydrolysis of the peptide yields Arg, 2 Gly, Ile, 3 Leu, 2 Lys, 2 Met, 2 Phe, Pro, Ser, 2 Tyr, and Val. Treatment with Edman's reagent releases PTH-Gly.
Carboxypeptidase A releases Phe.
Treatment with cyanogen bromide yields the following three peptides:
1. Gly-Leu-Tyr-Phe-Lys-Ser-Met
2. Gly-Leu-Tyr-Lys-Val-Ile-Arg-Met
3. Leu-Pro-Phe
Treatment with trypsin yields the following four peptides:
1. Gly-Leu-Tyr-Phe-Lys
2. Ser-Met-Gly-Leu-Tyr-Lys
3. Val-Ile-Arg 4. Met-Leu-Pro-Phe
Solution :
1. It is given that when Edman's reagent is used, it releases PTH-Glycin. The degradation of Edmans is used for the amino acids to sequencing of the peptide/protein and is also removes N terminal amino acid and thus gives us the PTH amino acid product.
Therefore, the first amino acid is Glycine.
2. The Carboxypeptidase A releases the C terminal amino acid, and therefore the last amino acid is Phe.
3. The Cyanogen Bromide helps to chop after the Med residue, therefore the sequence is 1 - 2 - 3 or 2 - 1 - 3.
4. The trysin chops after the basic amino acid - Arg and the Lys unless followed by Proline and so the sequence of the peptide is 1 - 2 - 3 4.
Aldehydes and ketones are converted into alkenes by means of a direct nucleophilic addition called the Wittig reaction.
a. True
b. False
Answer:
The given statement- Aldehydes and ketones are converted into alkenes by means of a direct nucleophilic addition called the Wittig reaction, is True.
Explanation:
The Wittig reaction converts aldehydes and ketones into alkenes through a simple nucleophilic addition. A triphenylphosphorine ylide, also known as a phosphorane, reacts with an aldehyde/ketone to produce an oxaphosphetane, a four-membered cyclic intermediate. Instead of being isolated, the oxaphosphetane decomposes spontaneously to release triphenylphosphine oxide and an alkene.
In an SN2 reaction, triphenylphosphine, a good nucleophile, reacts with a primary alkyl halide, followed by deprotonation of the carbon with a solid base, such as butyllithium, to form the ylide. In the product alkene, the carbonyl carbon and the carbon initially bound to the halogen become two carbons with a double bond.
The Wittig reaction's true worth lies in its ability to produce an alkene with a predictable structure, as the C=C bond forms exactly where the C=O bond did in the reactant, with no isomers (other than E/Z isomers) forming.
Hence , the correct option is (A) True.
Which item isn't a resource?
food
shelter
temperature
available mates
Answer:
temperature
Explanation:
hope this helps
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:
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