Please help with this one
Answer:
15g
Explanation:
hope this helped
We can use thin layer chromatography to check if Starbuck coffee has caffeine.
True
False
Answer:
false?
Explanation:
Gram for gram, fats in food have much more chemical energy than sugar. One component of fat is stearic acid, C18H36O2. When a sample of 1.02 g of stearic acid was burned completely in a bomb calorimeter, the temperature of the calorimeter rose by 4.26oC. The heat capacity of the calorimeter was 9.43 kJ/oC. Calculate the molar heat of combustion of stearic acid in kilojoules per mole.
Answer:
[tex]\mathbf{-1.12 \times 10^4 \ kJ/mol}[/tex]
Explanation:
Given that:
mass (m) of the sample = 1.02 g
number of moles of stearic acid [tex]=\dfrac{mass}{molar mass}[/tex]
[tex]= \dfrac{1.02 \ g}{284.49 \ g/mol} \\ \\ = 0.000358 \ moles[/tex]
The change in temp. [tex]\Delta T = 4.26^0 \ C[/tex]
heat capacity of the calorimeter (c) = 9.43 kJ/° C
Thus, heat due to reaction = cΔT
= 9.43 kJ/° C × 4.26° C
= 40.17 kJ
The heat in kJ/mol = [tex]\dfrac{40.17 \ kJ}{0.00358 \ mol}[/tex]
= 11204.23 kJ/mol
= 1.12 × 10⁴ kJ/mol
As a result of the reaction is exothermic, the heat reaction of the combustion is:
[tex]\mathbf{-1.12 \times 10^4 \ kJ/mol}[/tex]
during evaporation, the volume of the liquid decreases and the liquid becomes what???
Answer:
Evaporation happens when a liquid substance becomes a gas. When water is heated, it evaporates. The molecules move and vibrate so quickly that they escape into the atmosphere as molecules of water vapor. ... Once water evaporates, it also helps form clouds
Please Need help asap
For Al, its atomic number is 13 and its mass number is 27. How many neutrons does it have?
А. 13
B. 14
C. 26
D. 27
E. 40
Answer:
A
Explanation:
The number of protons and neutrons of an element is the same. the electrons are the only thing that can differ. The atomic number equal the protons and neutrons.
Due today please answer! Can we make electricity in the ocean?
1: Certainly can
2: No way
3: Yes but fossil fuels will pollute the water and the air
4: Yes by grabbing on to an electric eel
Answer:
3
Explanation: good luck dude I believe in u
Which vitamin is responsible for ricket disease
Answer:
Explanation:
Vitamin D deficiency rickets can be caused by a lack of vitamin D in the diet, a lack of exposure to the sun, or malabsorption syndromes such as celiac disease, in which there is an inability of the intestines to adequately absorb nutrients from foods.
Risk Factors: Diet (nutrition); Dark skin
Joan performed a shadow puppet play for her younger brother by shining a flashlight on paper cutouts behind a curtain. What happens to the light from the flashlight?
Answer:
The light is transmitted through the curtain.
Explanation:
I believe this might be the answer, please comment if it’s incorrect
Reaction intermediates differ from activated complexes in that A. they are stable molecules with normal bonds and are frequently isolated. B. they are molecules with normal bonds rather than partial bonds and can occasionally be isolated. C. they are intermediate structures which have characteristics of both reactants and products. D. they are unstable and can never be isolated. E. all reactions involve reaction intermediates, but not all have activated complexes.
Answer:
they are molecules with normal bonds rather than partial bonds and can occasionally be isolated.
Explanation:
In chemistry, reaction intermediates are species that are formed from reactants and are subsequently being transformed into products as the reaction progresses. In other words, reaction intermediates are species that do not appear in a balanced reaction equation but occur somewhere along the reaction mechanism of a non-elementary reaction. They are usually short lived species that possess a high amount of energy. They may or may not be isolated.
They are often molecular species with normal bonds unlike activated complexes that are sometimes hypervalent species.
Question 10
1 pts
Given the following balanced chemical equation:
2C2H10 + 902 +4CO2 + 10H2O
How many grams of C2H10 are needed to produce 150. g of water?
396 g
15.8 g
O 1420
O 56.8 g
Answer:
56.8 g
Explanation:
Your first conversion factor is the molar mass of H2O to convert from grams of water to moles. Your second conversion factor is the mole ratio of 2 mol C2H10 for every 10 mol H2O. Your last conversion factor is the molar mass of C2H10 to convert from moles back to grams.
150. g H2O • (1 mol H2O / 18.02 g H2O) • (2 mol C2H10 / 10 mol H2O) • (34.1 g C2H10 / 1 mol C2H10) = 56.8 g C2H10
Describe two realistic demands protestors could bring forward in their peaceful protest so that they dont face the same situation in future
Answer:
I do not know the Answer I'm just trying to get my point
Explanation:
Thank You
The two realistic demands protestors could bring forward in their peaceful protest include:
Adequate securityProvision of social amenities.Who is a Protester?Thus it is referred to an individual which publicly demonstrates opposition to something.One of the roles of the government is to protect lives and properties.
Making realistic demands during a peaceful protest is looked into in most cases.
Read more about Protester here https://brainly.com/question/11505871
Q3: Match the column A with Column B and write answer in Column C
Answer:
ok
Explanation:
1d
2c
3b
4a
Consider the following scenario
A drought hits the habitat of a semi-aquatic bird population. All ponds dry up, and fish populations decline. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, while short-legged birds eat insects. The drought has little effect on insect populations
What is the main selective pressure in this scenario?
Oleg length
Odrought
Ofish population
Oinsect population
Answer: b
Explanation: jk
Which overall chemical equation is obtained by combining these intermediate equations?
Be sure to answer all parts.
Find the pH during the titration of 20.00 mL of 0.1000 M triethylamine, (CH3CH2)3N (Kb = 5.2 × 10−4), with 0.1000 M HCl solution after the following additions of titrant.
20.20 mL:
pH =
a.
Initial moles of (CH₃CH₂)₃N = (0.1000 mol/L) × (20.00/1000 L) = 0.002 mol
Moles of HCl added = (0.1000 mol/L) × (13.00/1000 L) = 0.0013 mol
Addition of 1 mole of HCl reacts with 1 mole of (CH₃CH₂)₃N to 1 mole of (CH₃CH₂)₃NH⁺.
After addition of 13.00 mL of HCl:
Moles of (CH₃CH₂)₃N left unreacted = (0.002 - 0.0013) mol = 0.0007 mol
Moles of (CH₃CH₂)₃NH⁺ produced = 0.0013 mol
Hence, [(CH₃CH₂)₃NH⁺]/[(CH₃CH₂)₃N] = 0.0013/0.0007 = 13/7
Consider the dissociation of (CH₃CH₂)₃N:
(CH₃CH₂)₃N(aq) + H₂O(l) ⇌ (CH₃CH₂)₃NH⁺(aq) + OH⁻(aq) …… Kb = 5.2 × 10⁻⁴
Henderson-Hasselbalch equation:
pOH = pKb + log([(CH₃CH₂)₃NH⁺]/[(CH₃CH₂)₃N])
pOH = -log(5.2 × 10⁻⁴) + log(13/7) = 3.55
pH = pKw - pOH = 14.00 - 3.55 = 10.45
====
b.
Initial moles of (CH₃CH₂)₃N = 0.002 mol
Moles of HCl added = (0.1000 mol/L) × (20.80/1000 L) = 0.00208 mol
HCl is in excess.
Moles of HCl left unreacted = (0.00208 - 0.002) mol = 0.00008 mol
Volume of the final solution = (20.00 + 20.80) mL = 40.8 mL = 0.0408 L
In the final solution:
[H₃O⁺] = [HCl] = (0.00008 mol) / (0.0408 L) = 0.00196
pH = -log[H₃O⁺] = -log(0.00196) = 2.71
====
c.
Initial moles of (CH₃CH₂)₃N = 0.002 mol
Moles of HCl added = (0.1000 mol/L) × (29.00/1000 L) = 0.0029 mol
HCl is in excess.
Moles of HCl left unreacted = (0.0029 - 0.002) mol = 0.0009 mol
Volume of the final solution = (20.00 + 29.00) mL = 49 mL = 0.049 L
In the final solution:
[H₃O⁺] = [HCl] = (0.0009 mol) / (0.049 L) = 0.0184
pH = -log[H₃O⁺] = -log(0.0184) = 1.74
Which equation represents a double replacement reaction? A) 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g) B) 2Al(s) + 3Cl2(g) - 2AlCl3(s) C) 2AlCl3(s) + 2Al(s) + 3Cl2(g) D) AlCl3(aq) + 3KOH(aq) - Al(OH)3(s) + 3KCl(aq)
Answer:
D) AlCl₃(aq) + 3 KOH(aq) → Al(OH)₃(s) + 3 KCl(aq)
Explanation:
Which equation represents a double replacement reaction?
A) 2 Al(s) + 6 HCl(aq) → 2 AlCl₃(aq) + 3 H₂(g)
No, this is a single replacement reaction, in which Al replaces H in its acid.
B) 2 Al(s) + 3 Cl₂(g) → 2 AlCl₃(s)
No, this is a synthesis reaction, in which two simple substances combine to form a compound.
C) 2 AlCl₃(s) → 2 Al(s) + 3 Cl₂(g)
No, this is a decomposition reaction, in which a compound decomposes into simple substances.
D) AlCl₃(aq) + 3 KOH(aq) → Al(OH)₃(s) + 3 KCl(aq)
Yes, this is a double replacement reaction, in which both reactants exchange their cations and anions.
How many moles of hydrogen are needed to react with 0.234 mol oxygen according to this equation? 2H2 + O2 -> 2H2O
The number of moles of hydrogen to be 0.468.
The balanced chemical equation :
2H₂ + O₂ → 2H₂O
This implies that 2 moles of hydrogen and one mole of oxygen are required to produce 2 moles of water.
or
Thus molar ratio of ( H₂ : O₂)= 2 : 1.
So, it requires double the moles of oxygen to get the required moles of water.
Number of moles of oxygen= 0.234 mol
So following the molar ratio concept:
We will get:
The number of moles of hydrogen to be 0.468.
Learn more:
brainly.com/question/21911991
3 attempts left
Check my work
Enter your answer in the provided box.
The pressure inside a 1.0 L balloon at 25°C was 750 mm Hg. What is the pressure (in mmHg) inside the
balloon when it is cooled to -65°C and expands to 3.3 L in volume?
mm Hg
Answer:
shhsss×<×>×××<××××
Explanation:
4×738×8<#329×
a solution of KCl in water has a concentration of 0.243 M. The solution has a volume of 0.580 L. How many grams of KCl are present in the solution?
Answer:
10.5 g
Explanation:
Step 1: Given data
Molar concentration of the solution (C): 0.243 MVolume of solution (V): 0.580 LStep 2: Calculate the moles of solute (n)
Molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
n = M × V
n = 0.243 mol/L × 0.580 L = 0.141 mol
Step 3: Calculate the mass corresponding to 0.141 moles of KCl
The molar mass of KCl is 74.55 g/mol.
0.141 mol × 74.55 g/mol = 10.5 g
Which of the following statements is true????
Sedimentary rock is usually found in areas which have, or once had, water.
According to the theory of continental drift, the continents are formed from small islands which drifted together.
Seasons happen because the Earth is farther away from the sun during the winter than during the summer.
Metamorphic rock is formed from small rock fragments cemented by water.
Answer:
I believe it is C?
Sorry fi it doesn't help!
Due today please answer! Can we better understand plastics by using Periodic Table?
Answer is in a photo. I can only upload it to a file hosting service. link below!
bit.[tex]^{}[/tex]ly/3a8Nt8n
Answer:
I think not
Explanation:
Plastics can be understand through the knowledge of its types and structure than periodic table.
The product(s) of a heated reaction of N,N-ethylmethylpentanamide with sodium hydroxide would be __________. View Available Hint(s) The product(s) of a heated reaction of N,N-ethylmethylpentanamide with sodium hydroxide would be __________. sodium pentanoic acid and ethylmethylamine pentanoic acid and ethylmethylamine sodium propanoate and pentylamine sodium pentanoate and ethylmethylamine
Answer:
sodium pentanoate and ethylmethylamine
Explanation:
The reaction of N,N-ethylmethylpentanamide with sodium hydroxide involves an amide and an inorganic hydroxide.
The CO-N bond is highly polar hence the -N(C2H5) (CH3) moiety is easily lost and replaced by the -ONa leading to the formation of sodium pentanoate.
The H^+ combines with -N(C2H5) (CH3) to yield ethylmethylamine
The combustion of coal, a fossil fuel, to produce electrical energy produces a by-product, sulfur dioxide, which is emitted into the atmosphere. Sulfur dioxide will mix with the components in the atmosphere to produce _____.
Forest Fires
Global warming
Acid Rain
Algae growing in ponds and lakes
What is the molar mass of AlCl3
Answer:
133.34 g/moles
Explanation:
but to make life easy it could be 133.4 g/ moles as well
how is the periodic table important for all of science and not just chemistry? pleas answer me
Answer:
The periodic table has been there for such a long time and how it is helpful in all science it is the element itself. How the element is used in real life. For example, oxygen is used in the atmosphere. Plants use carbon in order to covert it into oxygen more like that
Please write the answer in format below
Answer:
0.95 L
Explanation:
Step 1: Given data
Concentration of the Mg(NO₃)₂ solution (C): 0.32 M (0.32 mol/L)
Mass of Mg(NO₃)₂ (solute): 45 g
Step 2: Calculate the moles corresponding to 45 g of Mg(NO₃)₂
The molar mass of Mg(NO₃)₂ is 148.33 g/mol.
45 g Mg(NO₃)₂ × 1 mol Mg(NO₃)₂ /148.33 g Mg(NO₃)₂ = 0.303 mol Mg(NO₃)₂
Step 3: Calculate the volume of solution that contains 0.303 moles of Mg(NO₃)₂
The concentration of the solution is 0.32 M, that is, there are 0.32 moles of Mg(NO₃)₂ per liter of solution.
0.303 mol Mg(NO₃)₂ × 1 L Solution / 0.32 mol Mg(NO₃)₂ = 0.95 L
2. Water is an excellent solvent. With water being a polar
molecule, it can be an especially strong solvent for other
polar molecules. Give an example of how water acting as a
solvent is important for living organisms.
NO LINKS PLZ HELP
Answer:
Water acts as a solvent of carbon dioxide excreted from tissues, in blood and helps in regulating pH (because it forms carbonic acid that lowers pH when it tends to get higher). Blood pH should be maintained at about 7.4. One major reason is that the structure of protein is dependent ton pH because pH determines its ionization hence also affecting the charges and interaction between side groups of amino acids. A change in pH may, therefore, denature proteins and negatively affect cellular functions.
Explanation:
To get more on how water acts as a universal solvent check out brainly.com/question/7007192
Which is an application of genetic engineering?
A.
destroying all bacteria
B.
creating synthetic insulin
C.
producing cells from nonliving material
D.
preventing weeds from spreading to farmland
Answer:
B. Creating synthetic insulin
Explanation:
In medicine, genetic engineering has been used to mass-produce insulin, human growth hormones, Follistim (for treating infertility), human albumin, monoclonal antibodies, antihemophilic factors, vaccines, and many other drugs. In research, organisms are genetically engineered to discover the functions of certain genes.
1.Calculate the percentage of the components of the compounds resulting from the following reactions
(A) 222.6g N combined fully with 77.4g of O.
(B) Decomposition of table salt which yields 2.62g of Na and 4.04g of Cl.
Answer:
Explanation:
I believe its A
Plz help me well mark brainliest if you are correct!
Answer:
c: heat and erosine
Explanation: