Answer:
question 1 answer is b
Explanation:
istopes equal to same atomic number but different mass number
can someone please help me? i will give brainliest
As part of a soil analysis on a plot of land, a scientist wants to determine the ammonium content using gravimetric analysis with sodium tetraphenylborate, Na+B(C6H5)−4. Unfortunately, the amount of potassium, which also precipitates with sodium tetraphenylborate, is non‑negligible and must be accounted for in the analysis. Assume that all potassium in the soil is present as K2CO3 and all ammonium is present as NH4Cl.
A 5.025 g soil sample was dissolved to give 0.500 L of solution. A 100.0 mL aliquot was acidified and excess sodium tetraphenylborate was added to precipitate both K+ K + and NH+4 ions completely.
Compound Formula mass
B(C6H5)−4+K+⟶KB(C6H5)4(s) KB(C6H5)4 358.33 g/mol
B(C6H5)−4+NH+4⟶NH4B(C6H5)4(s) NH4B(C6H5)4 337.27 g/mol
K2CO3 138.21 g/mol
NH4Cl 53.492 g/mol
The resulting precipitate amounted to 0.277 g. A new 200.0 mL aliquot of the original solution was made alkaline and heated to remove all of the NH+4 as NH3. The resulting solution was then acidified, and excess sodium tetraphenylborate was added to give 0.105 g of precipitate.
Find the mass percentages of NH4Cl and K2CO3 in the original solid.
______ %NH4CL
______ %K2CO3
Answer:
Mass percentage of NH₄Cl = 3.54%
Mass percentage of K₂CO₃ = 1.01%
Explanation:
If a 200.0 mL aliquot produced 0.105 g of KB(C₆H₅)₄, then a 100.0 mL aliquot would produce 1/2 * 0.105 g = 0.0525 g of KB(C₆H₅)₄.
Therefore, mass of NH₄B(C₆H₅)₄ in the 100.0 ml aliquot = (0.277 - 0.0525)g = 0.2245 g
Number of moles of NH₄B(C₆H₅)₄ in 0.2245 g = 0.2245 g/ 337.27 g/mol = 0.0006656 moles
In 500 ml solution, number of moles present = 0.0006656 * 500/100 = 0.003328 moles.
From equation of the reaction; mole ratio of NH₄⁺ and NH₄B(C₆H₅)₄ = 1:1
Similarly, mole ratio of NH₄⁺ and NH₄Cl = 1:1
Therefore, moles of NH₄Cl in 500 ml sample = 0.003328 moles
Mass of NH₄Cl = 0.003328 mol * 53.492 g/mol = 0.178 g
Mass percentage of NH₄Cl = (0.178/5.025) * 100% = 3.54%
Number of moles of KB(C₆H₅)₄ in 0.105 g (precipitated from 200.0 ml aliquot) = 0.105 g/ 358.33 g/mol = 0.000293 moles
In 500 ml solution, number of moles present = 0.000293 * 500/200 = 0.0007326 moles.
From equation of the reaction; mole ratio of K⁺ and KB(C₆H₅)₄ = 1:1
Similarly, mole ratio of K⁺ and K₂CO₃ = 2:1
Therefore, moles of K₂CO₃ in 500 ml sample = 0.0007326/2 moles = 0.0003663 moles
Mass of K₂CO₃ = 0.0003663 mol * 138.21 g/mol = 0.05063 g
Mass percentage of K₂CO₃ = (0.05063/5.025) * 100% = 1.01%
One differentiating characteristic between vascular and nonvascular plants is the lack of active transport structures in the nonvascular plants. How does the lack of xylem or phloem contribute to the smaller size of the nonvascular plants?
Nonvascular plants are smaller because xylem and phloem help a plant stand up taller.
Nonvascular plants have other transport structures that are microscopic and therefore take up less room.
Nonvascular plants rely upon concentration gradients to move food and water, which only works over small distances.
Nonvascular plants are smaller because they don’t photosynthesize as much as vascular plants and don’t get enough food.
Answer:
One of the most important characteristics of non-vascular plants is the absence of vascular tissues. Non-vascular plants do not have the vascular tissues known as xylem and phloem. ... As they do not have any vascular tissue, they cannot retain water for long time or transport it to other parts of the plant.
Explanation:
Answer:
fern
Explanation:
__Hgo > __Hg + __O2?
Hg + O2 → HgO
✅Word equation: Mercury + Oxygen gas → Mercury (II) oxide
✅ Type of Chemical Reaction: For this reaction we have a combination reaction.
✅ Balancing Strategies: To balance this equation it's probably easiest to begin by changing the coefficient in front of the HgO.
This is a combination reactions because the mercury (Hg) plus the oxygen gas (O2) come together to form the Mercury (II) oxide (MgO).
Hint-1
Hint-2
IamSugarBee
what can i do to change the material like metal clothes line or washing line
I'm not sure bro but i will try for you
8 is subtracted from the square of a number.
Answer:
how do I answer without context
Lily feels tired and weak in the evenings after work. Before starting her chores, she eats dinnner. Which characteristic of life does Lily Exhibit?
Answer:
cool
Explanation:
The mass of 1 gram:
is kept as a standard platinum cylinder in France
equals 1 cm³
is .01 kg
equals the mass of 1 mL of water at 4°C
Answer:
C. equals the mass of 1 mL of water at 4°C
Explanation:
PLEASE HELP ME ASAP!
Which of the following elements has the highest electronegativity?
A. Ar
B. Ga
C. Ag
D. S
Answer:
its S
Explanation:
What is the frequency of a photon of light (in Hz) that has an energy of 2.50 x 10-18 J?
Answer:
The answer is
[tex]3.77 \times {10}^{15} \: \: \: Hz[/tex]
Explanation:
The frequency of the photon can be found by using the formula
[tex]f = \frac{E}{h} \\ [/tex]
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
E = 2.50 × 10^-18 J
So we have
[tex]f = \frac{2.50 \times {10}^{ - 18} }{6.626 \times {10}^{ - 34} } \\ [/tex]
We have the final answer as
[tex]3.77 \times {10}^{15} \: \: \: Hz[/tex]
Hope this helps you
HELPPP
Which of the following pairs of elements is most likely to permanently transfer one or more electrons to the
other element?
a. Chlorine and phosphorus
b. Iron and bromine
c. Tin and lead
d. Nitrogen and oxygen
Alison finds the total mass of a sample of baking soda, a balloon, and a glass container with vinegar in it. She adds the baking soda to the vinegar and immediately places the balloon over the mouth of the container.
Answer:
The baking soda and vinegar react to create carbon dioxide, which inflates the balloon.
Explanation:
What are the four main types of tissues in the human body?
Answer:
epithelial tissue, connective tissue, muscle tissue, and nerve tissue
Explanation:
The smallest possible particle of an element is a(n)
RE
??
Answer:
An atom is the smallest particle of an element that still has the properties of that element. Atoms, in turn, are composed of subatomic particles, including negative electrons, positive protons, and neutral neutrons. The number of protons in an atom determines the element it represent
Explanation:
What ingredients can be alternative for cornstarch?
Answer:
their are many alternative for cornstarch.But I know only 10 of them and they are:
1.Rice Flour
2.wheat Flour
3.Potato Starch
4.Arrowroot
5.Tapioca
6.Ground Flaxseeds
7.Gaur Gum
8.Xanthan Gum
9.Glucomannan
10.Xanthan Gum
Which element requires the least amount of energy to remove the most loosely held electron from a gaseous atom in the ground state? 1. K 2. Kr 3. As 4.br
Answer:
K
Explanation:
Why do you think the hot red water sank to the bottom?
Answer:
i did this in school :) but Hot water will rise to the top because it is less dence and cold water will sink to the bottom because it is more dence
Explanation:
is beeswax a mineral, a rock or neither
Answer:
niether
Explanation:
Beeswax is neither a mineral nor a rock it is supposed to be a heterogenous mixture.
What are minerals?
Minerals are defined as a chemical compound which has a well -defined composition and possesses a specific crystal structure.It occurs naturally in the pure form.
If a compound occurs naturally in different crystal structure then each structure is considered as a different mineral.The chemical composition of a mineral varies depending on the presence of small impurities which are present in small quantities.
Some minerals can have variable proportions of two or more chemical elements which occupy equivalent position in the crystal structure.It may also have variable composition which is split into separate species.
Physical properties of minerals include color,streak, luster,specific gravity and cleavage.
Learn more about minerals,here:
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Write a balanced equation for each of the acid-base reaction given below.a. Aqueous sulfuric acid with aqueous potassium hydroxide.
Answer:
H2SO4 + 2KOH => K2SO4 + 2H2O
Explanation:
The acid-base reaction is a type of chemical reaction that involves the exchange of hydrogen ions.
The acid-base reaction between aqueous sulfuric acid ( H2SO4 ) and aqueous potassium hydroxide (KOH) is a neutralization reaction that results in potassium sulfate and water.
sulfuric acid + potassium hydroxide => potassium sulfate + water
So, the balanced equation for this reaction is as follows:
H2SO4 + 2KOH => K2SO4 + 2H2O
Hence, the correct answer is "H2SO4 + 2KOH => K2SO4 + 2H2O".
How is the term stable used in the text?
Answer:
When something is stable, it's fixed and steady. If you needed advice, you'd probably go to your most stable friend, the one least likely to act crazy or be easily upset.
Explanation:
Whether you're talking about an object or a person, the adjective stable implies reliability and strength. You can describe a government as stable, or a relationship, or a desk. A completely different meaning of stable is the noun "building used for housing horses or other animals." Both senses of the word come from the Latin stabilis, "firm or steadfast."
Chemistry pick two answers
Which properties of grains determine the texture of rocks? Check all that apply.
feel
pattern
color
shape
size
I will mark Brainlyest
Answer:
color shape and size
Explanation:
answer this question
Answer:
The first one
Explanation:
A chemist is asked to determine the specific heat capacity of an unknown mineral. The 149-g sample was heated to 92.7°C and placed into a calorimeter containing 81.4 g of water at 20.0°C. The heat capacity of the calorimeter was 12.8 J/K. The final temperature in the calorimeter was 23.7°C. What is the specific heat capacity (in J/g°C) of the mineral? Enter to 4 decimal places.
Answer:
The specific heat of the mineral is 0.1272J/g°C
Explanation:
The sample is given energy to the calorimeter and the sample of water.
The energy released for the sample is equal to the energy absorbed for both the calorimeter and the water:
C(Sample)*m*ΔT = C(Calorimeter)*ΔT + C(water)*m*ΔT
Where C is specific heat
m is mass of the sample and water
And ΔT is change in temperature
C(Sample)*149g*(92.7°C-23.7°C) = 12.8J/K*(23.7°C-20.0°C) + 4.184J/g°C*81.4g*(23.7°C-20.0°C)
C(Sample)*10281g°C = 47.36J + 1260.1J
C(Sample) = 0.1272J/g°C
The specific heat of the mineral is 0.1272J/g°C
The specific heat of the mineral is 0.1272J/g°C
Calculation of the specific heat:
The energy released for the sample should be equivalent to the energy absorbed for both the calorimeter and the water:
So,
C(Sample)*m*ΔT = C(Calorimeter)*ΔT + C(water)*m*ΔT
here C is specific heat
m is mass of the sample and water
And ΔT is change in temperature
Now
C(Sample)*149g*(92.7°C-23.7°C) = 12.8J/K*(23.7°C-20.0°C) + 4.184J/g°C*81.4g*(23.7°C-20.0°C)
C(Sample)*10281g°C = 47.36J + 1260.1J
C(Sample) = 0.1272J/g°C
learn more about heat here: https://brainly.com/question/15873257
Water is composed of one atom of oxygen and two atoms of
Answer:
Hydrogen.
Explanation:
You've probably seen "[tex]H_{2}0[/tex]" which is the formula for water. It means that there's 2 hydrogen atoms, and one oxygen atom, in one molecule of water.
Hope this helps! Feel free to mark me Brainliest if you feel this helped. :)
Answer:
the answer is H. (hydrogen)
The water cycle would not be possible without ______ and ________.
a. evaporation; condensation
b. gravity; sun
c. precipitation; rain
d. gravity; precipitation
List the factors that cause low oxygen levels.
Answer:
Common causes of hypoxemia include:
Anemia.
ARDS (Acute respiratory distress syndrome)
Asthma.
Congenital heart defects in children.
Congenital heart disease in adults.
COPD (chronic obstructive pulmonary disease) exacerbation — worsening of symptoms.
Emphysema.
Interstitial lung disease
and many more.....
What is the density of aluminium? |
एल्यूमीतनयम का घनत्व कतना होता है?
A : 2.7 g/cm3 | 2.7 g/cm3
B : 3.7 g/cm3 | 3.7 g/cm3
C : 4.7 g/cm3 | 4.7 g/cm3
D : 5.7 g/cm3 | 5.7 g/cm3
Ans: A : 2.7 g/cm3 | 2.7 g/cm3
Answer:
answer 2.7
Explanation:
a.2.7g/cm3
illustrate the respiratory system
I hope this has the information that you need
According to the law of superposition, where would you find objects with an older relative age?
Answer:
The law of superposition states that each rock layer is older than the one above it. So, the relative age of the rock or fossil in the rock is older if it is farther down in the rock layers.