Answer:
B
Explanation:
Mass is defined as the quantity of matter in an object.
9th grade science need help ASAP
Answer:
D
Explanation:
It is a solid everything that is a solid is heavier
What is the pH of a solution made by mixing 0.050 mol of NaCN with enough water to make a liter of solution
Answer:
pH = 11
Explanation:
The equilibrium of a weak base as NaCN in water is:
NaCN(aq) + H₂O(l) ⇄ OH⁻(aq) + Na⁺(aq) + HCN(aq)
And kb, the equilibrium constant, is:
Kb = [OH⁻] [HCN] / [NaCN]
Where Kb of NaCN is 2.04x10⁻⁵
In the beginning, the [NaCN] is 0.050mol / L = 0.050M.
Both [OH⁻] and [HCN] are produced from this equilibrium, and its concentration is X, that is:
2.04x10⁻⁵ = [X] [X] / [0.050M]
1.02x10⁻⁶ = X²
X = 1x10⁻³ = [OH⁻]
As pOH = - log [OH⁻]
pOH = 3.00
And pH = 14 - pOH
pH = 11
Rearange the equation to isolate a. (a+b/c)(d-e)=f find a =
Answer:
[tex]a=\frac{f}{d-e}-\frac{b}{c}[/tex]
Explanation:
Hello.
In this case, for the equation:
[tex](a+b/c)(d-e)=f[/tex]
For isolating a, we must first pass (d-e) to divide at the other side as it is initially multiplying:
[tex]a+b/c=\frac{f}{(d-e)}[/tex]
Next, as b/c is adding, it passes to subtract at the other side in order to finally isolate a:
[tex]a=\frac{f}{d-e}-\frac{b}{c}[/tex]
Best regards!
Calculate the fractional saturation for hemoglobin when the partial pressure of oxygen is 40 mm Hg. Assume hemoglobin is 50%% saturated with oxygen at a partial pressure of 22 mm Hg and that the Hill coefficient is 3.
Answer:
The fractional saturation for hemoglobin is 0.86
Explanation:
The fractional saturation for hemoglobin can be calculated using the formula
[tex]Y_{O_{2} } = \frac{(P_{O_{2} })^{h} } {(P_{50})^{h} + (P_{O_{2} })^{h} }[/tex]
Where [tex]Y_{O_{2} } \\[/tex] is the fractional oxygen saturation
[tex]{P_{O_{2} }[/tex] is the partial pressure of oxygen
[tex]P_{50}[/tex] is the partial pressure when 50% hemoglobin is saturated with oxygen
and h is the Hill coefficient
From the question,
[tex]{P_{O_{2} }[/tex] = 40 mm Hg
[tex]P_{50}[/tex] = 22 mm Hg
h = 3
Putting these values into the equation, we get
[tex]Y_{O_{2} } = \frac{(P_{O_{2} })^{h} } {(P_{50})^{h} + (P_{O_{2} })^{h} }[/tex]
[tex]Y_{O_{2} } = \frac{40^{3} }{22^{3} + 40^{3} }[/tex]
[tex]Y_{O_{2} } = \frac{64000 }{10648 + 64000 }[/tex]
[tex]Y_{O_{2} } = \frac{64000 }{74648 }[/tex]
[tex]Y_{O_{2} } = 0.86[/tex]
Hence, the fractional saturation for hemoglobin is 0.86.
The numbers represent the change in energy for a chemical reaction. They are calculated by subtracting the energy of products from the energy of reactants. Which number would result from an endothermic reaction?
Answer:
800
Explanation:
took the test and got it right
The numbers represent the change in energy for a chemical reaction. They are calculated by subtracting the energy of products from the energy of reactants. 800 would result from an endothermic reaction.Therefore, the correct option is D.
What are the various types of reactions?
There are different types of reactions, such as the endothermic reaction, where the energy is used for the product's formation, and the exothermic reaction.
The energy is released in an exothermic reaction, resulting in a negative result, whereas the energy is used in an endothermic reaction, resulting in a positive result.
Any chemical reaction that absorbs heat from its surroundings is an endothermic reaction. The absorbed energy serves as the activation energy for the reaction to take place.
Thus, 800 would result from an endothermic reaction, the correct option is D.
Learn more about the types of reactions here.
brainly.com/question/23184814
#SPJ2
Your question is incomplete, most probably your question was
The numbers represent the change in energy for a chemical reaction. They are calculated by subtracting the energy of products from the energy of reactants. Which number would result from an endothermic reaction?
–212
0
-1
800
Does Sodium Chloride, have the same properties as sodium and chlorine
Which of the following is an example of physical change?
Answer: The glass cup falling
Explanation:
It didnt change chemically, only its physical appearance
if an ocean wave has a frequency of 2 hz and a speed of 4 m/s , what is the wavelength
Answer:2m
Explanation:
4/2=2
The wavelength will be "2 m".
Given values are:
Frequency,
f = 2 hzSpeed,
v = 4 m/sAs we know,
→ [tex]Frequency(f) = \frac{Speed (v)}{Wavelength (\lambda)}[/tex]
or,
→ [tex]\lambda = \frac{v}{f}[/tex]
By substituting the values, we get
→ [tex]=\frac{4}{2}[/tex]
→ [tex]= 2 \ m[/tex]
Thus the above response is correct.
Learn more about wavelength here:
https://brainly.com/question/9583725
1. What 2 subatomic particles have charges? List the particle name and its charge.
Answer: Proton - positive charge (+)
Neutron - neutral charge (0)
Electron - negative charge (-)
Explanation:
How many liters of H2(g) at STP are produced per gram of Al(s) consumed in the following reaction? 2Al(s)+6HCl(aq)→2AlCl3(aq)+3H2(g)
Answer:
1.24 L of H₂ at STP .
Explanation:
2Al(s) +6HCl(aq) → 2AlCl₃(aq) + 3H₂(g)
2 moles 3 x 22.4 L
2 x 27 g of Al reacts to give 3 x 22.4 L of H₂ at STP .
1 g of Al will react to give 3 x 22.4 / ( 2 x 27 ) L of H₂ at STP .
= 1.24 L of H₂ at STP .
The volume of hydrogen produced by 1 grams of Al has been 1.24 L.
The balanced chemical reaction has been given as:
[tex]\rm 2\;Al\;+\;6\;HCl\;\rightarrow\;2\;AlCl_3\;+\;3\;H_2[/tex]
From the equation, 2 moles of Aluminum gives 3 moles of Hydrogen
The mass of the compound from moles can be given as:
Mass = moles × molecular mass
Mass of 2 moles Al = 2 × 27 g
Mass of 2 moles Al = 54 g
Mass of 3 moles hydrogen = 3 × 2 g
Mass of 3 moles hydrogen = 6 g
From the equation,
54 g aluminum gives = 6 grams hydrogen
[tex]\rm 1\;gram\;aluminum\;=\;\dfrac{6}{54}\;\times\;1[/tex]
1 gram Aluminum = 0.11 grams hydrogen
The mass of hydrogen produced by 1 gram Al has been 0.11g. The moles equivalent to 0.11g hydrogen has been given as:
Mass = moles × molecular mass
0.11 g = moles × 2 g/mol
Mole of hydrogen = 0.055 mol
The moles of hydrogen produced by 1 gram of Al has been 0.055 mol.
According to the ideal gas equation, any gas at STP has 1 mole equivalent to 22.4 L. So,
1 mol = 22.4 L
0.055 mol = 0.055 × 22.4 L
0.055 mol = 1.244 L.
The volume of hydrogen produced by 1 grams of Al has been 1.24 L.
For more information about volume at STP, refer to the link:
https://brainly.com/question/11676583
Bromine is found above iodine in Group 17 of the periodic table. If an ion formed by bromine has a charge of 1-, what is the charge on an ion
formed by iodine?
A. -7
B. -2
C. -1
D. +1
Answer:
Explanation:
Iodine is the most flexible of the atoms in Group 17 of the periodic table. It can have more than 1 charge, especially when combined with oxygen. The answer that you are expected to give, I think is C. Iodine's dominant charge is - 1
During the analysis, 0.00905 mol H2O is formed. Calculate the amount (mol) H in 0.00905 mol H2O.
Answer:
0.0181 mol H
Explanation:
Step 1: Given data
Moles of water (H₂O) formed during the analysis: 0.00905 mol H₂O
Step 2: Calculate the amount (mol) H in 0.00905 mol H₂O
According to the chemical formula of water, the molar ratio of water to hydrogen is 1:2, that is, there are 2 moles of H per 1 mole of H₂O. We will use this conversion factor to calculate the moles of H in 0.00905 moles of H₂O.
0.00905 mol H₂O × (2 mol H/1 mol H₂O) = 0.0181 mol H
1. Suppose you neglected to remove all the unreacted zinc from the reaction mixture. How would this affect the calculated percent yield of copper? Explain
Answer:
The percentage yield of copper will exceed 100%
Explanation:
In the presence of impurities, the percentage yield of a substance usually exceeds 100%.
This implies that, when the unreacted zinc impurity is not removed from the reaction mixture and the percentage yield of copper is calculated, the actual yield will become greater than the theoretical yield thereby making the percentage yield of copper to be above 100%
Please select the word from the list that best fits the definition
Represents a range of responses to a question:
Caption
Legend/Key
Scale
Answer:
The answer is B(scale)
Explanation:
Since the question asked about a range, the scale would be the most logical answer since scales are used to measure.
Answer:
the answer is C.
Explanation:
Calculate the number of moles of barium chloride in 427g of a 3.17%by mass barium chloride solution?a) 6.5x10^02molb) 7.83x10^02molc) 4.31x10^02mold) 7.81x10^02mole) 4.27x10^02mol
Answer:
The answer is "Option a".
Explanation:
Multiply the mass of the solutions by 3.17% to get the mass of [tex]BaCl_2[/tex]:
[tex]\to 427 \ g \times 0.0317 = 13.56\ g[/tex]
Divide this mass with BaCl2's molecular concentration to acquire the mole ratio:
[tex]molar mass = 208.24 \frac{g}{mol}\\\\moles = \frac{13.56}{208.24} = 0.065 \ moles \\\\[/tex]
[tex]= 6.5 \times 10^{-2} \ moles[/tex]
A 427 g sample is 3.17% by mass barium chloride contains 6.5 × 10⁻² moles of BaCl₂.
A 427 g sample is 3.17% by mass barium chloride, that is, there are 3.17 g of barium chloride per 100 g of sample.
The mass of barium chloride in 427 g of the sample is:
[tex]427gSample \times \frac{3.17gBaCl_2}{100gSample} = 13.5gBaCl_2[/tex]
We can calculate the number of moles in 13.5 g of barium chloride using its molar mass (208.23 g/mol).
[tex]13.5 g \times \frac{1mol}{208.23g} = 6.5 \times 10^{-2} mol[/tex]
A 427 g sample is 3.17% by mass barium chloride contains 6.5 × 10⁻² moles of BaCl₂.
Learn more: https://brainly.com/question/12127540
Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solutions. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP.
Required:
How many grams of KHP are needed to exactly neutralize 25.6 mL of a 0.527 M potassium hydroxide solution?
Answer:
2.75 g
Explanation:
The number of moles of KOH is obtained from the equation;
n=CV
C= concentration
V= volume of solution
n= 0.527 × 25.6/1000
n= 0.0135
Reaction equation;
KOH(aq) + KHC8H4O4(aq) --->(KC8H4O4)K(aq) + H2O(l)
1 mole of KHP reacts with 1 mole of KOH
Hence; 0.0135 moles of KHP reacts with 0.0135 moles of KOH
From;
Number of moles = reacting mass/molar mass
Reacting mass = 0.0135 × 204
= 2.75 g of KHP
a. Describe the molecule chlorine dioxide, CIO in terms of three possible resonance structures.
b. Do any of these resonance structures satisfy the octet rule for every atom in the molecule? Why or why not?
Answer:
See explanation
Explanation:
The compound ClO2 has 19 valence electrons. ClO2 is a bent molecule with tetrahedral electron pair geometry but has two lone pairs of electrons. This is indicated by the presence of four electron pairs on the outermost shell of the central atom.
The molecule has an odd number of valence electrons, hence, it is generally regarded as a paramagnetic radical. None of the proposed Lewis structures for the molecule is satisfactory because none of them obeys the octet rule.
From the images attached, one can easily see that the electron dots around the oxygen and chlorine atoms does not satisfy the octet rule in all the resonance structures shown.
Find the volume of an object that has a density 0f 3.14g/mL and a mass of 87.3g
Answer:
The answer is 27.80 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question
mass = 87.3 g
density = 3.14 g/mL
We have
[tex]volume = \frac{87.3}{3.14} \\ = 27.8025477...[/tex]
We have the final answer as
27.80 mLHope this helps you
Someone plz hello me ASAP it would be appreciated on question 9 btw
Answer:
C.
Explanation:
The water is being stored for the time being, and potential energy is, essentially, defined like that. Once the energy is utilized, it will turn into kinetic energy.
Which of the following compounds contains polar covalent bonds?
a) CS2
b) LiF
c) F2
d) CH3F
Answer:
no d
Explanation:
it has a permanent dipole
CH₃F compound contains polar covalent bonds in its structure, hence option D is correct.
This happens when the electronegativity of the relevant atoms differs significantly.
The electronegativities of the carbon and fluorine atoms in CH3F are dissimilar. Because fluorine is more electronegative than carbon, it attracts the shared electrons to it, giving the fluorine atom a partial negative charge and the carbon atom a partial positive charge.
A polar covalent bond is created as a result of this unequal charge distribution. CH₃F compound contains polar covalent bonds in its structure.
Learn more about polar covalent bond, here:
https://brainly.com/question/28295508
#SPJ2
A beam of electrons (m = 9.11 × 10-31 kg/electron) has an average speed of 1.9 × 108 m/s. What is the wavelength of electrons having this average speed, in picometers?
Answer:
12 pm
Explanation:
Step 1: Given data
Mass of an electron (m): 9.11 × 10⁻³¹ kgAverage speed of an electron (v): 1.9 × 10⁸ m/sSpeed of light (c): 3.00 × 10⁸ m/sPlanck's constant (h): 6.63 × 10⁻³⁴ J.sWavelength of an electron (λ): ?Step 2: Calculate the kinetic energy (E) of an electron
We will use the following expression.
E = 1/2 × m × v²
E = 1/2 × 9.11 × 10⁻³¹ kg × (1.9 × 10⁸ m/s)²
E = 1.6 × 10⁻¹⁴ J
Step 3: Calculate the wavelength of an electron
We will use the following expression.
E = h × c / λ
λ = h × c / E
λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 1.6 × 10⁻¹⁴ J
λ = 1.2 × 10⁻¹¹ m
Step 4: Convert "λ" to picometers
We will use the relationship 1 m = 10¹² pm.
1.2 × 10⁻¹¹ m × (10¹² pm/1 m) = 12 pm
The wavelength of the beam of electrons is 3.8 pm.
Using the De Broglie relation;
λ = h/mv
λ = wavelength
h = Plank's constant
m = mass of the object
v = speed of the object
Now;
λ = ?
h = 6.6 × 10^-34 Js
m = 9.11 × 10^-31 kg
v = 1.9 × 10^8 m/s
So;
λ = 6.6 × 10^-34 Js/ 9.11 × 10^-31 kg × 1.9 × 10^8 m/s
λ = 6.6 × 10^-34 /1.73 × 10^-22
λ = 3.8 × 10^- 12 m or 3.8 pm
Learn more: https://brainly.com/question/9743981
Which solution, NaCl(aq) or CH3OH(aq), conducts electricity?
Answer:
NaCl(aq)
Explanation:
Nacl(aq) is an electrolyte when it melts and it conducts electricity. This is due to the fact that when it is in solution, it dissociates to be Na+ and Cl-. These ions are conductors of electricity. It conducts electricity because of the movements and also the discharge of ions. CH3OH(aq) is not a conductor of electricity therefore the first option is the answer.
A bicycle rider is applying a force of 20 N while heading south against a wind blowing from the south with a force of 5 N
Answer:
the bike will go down 5 N
What is cellulose and what does it do?
Answer:
an insoluble substance which is the main constituent of plant cell walls and of vegetable fibers such as cotton. It is a polysaccharide consisting of chains of glucose monomers.
Cellulose is the main substance in the walls of plant cells, helping plants to remain stiff and upright. Humans cannot digest cellulose, but it is important in the diet as fibre. Fibre assists your digestive system – keeping food moving through the gut and pushing waste out of the body.
Explanation:
Answer:
Hello! The main chemical component in cell walls is a complex carbohydrate called cellulose. Cellulose is made of thousands of sugar molecules linked end to end. It is extremely durable, which makes it useful for paper, linen, and cotton products. So the answer to your question is: Cellulose is a very complex carbohydrate that is found in plant walls. In fact, it is the basic structural component in plant walls.
Explanation:
Hope this helped!
Why can we use a water-ethanol mixture but not a water-hexane mixture as a recrystallization solvent? because water and hexane are ___________________.
Answer:
immiscible liquids
Explanation:
When two liquids are to be used for the purpose of recrystallization the both liquids must be miscible with each other in all proportions.
This implies that, if two liquids are immiscible, it will be difficult for the mixture to be useful in recrystallization.
Water and hexane are immiscible because water is a polar solvent and hexane is a non polar solvent.
Water is miscible with ethanol because ethanol contains polar -OH groups that interact effectively with water leading to miscibility of ethanol with water in all proportions.
How many atoms are in one formula unit of the compound FeC5O5?
O 10
05
12
O 11
Answer: D) 11
Explanation:
We have 1 iron atom (the Fe)
We have 5 carbon (denoted [tex]C_5[/tex])
We have 5 oxygen atoms (denoted [tex]O_5[/tex])
So we have 1+5+5 = 11 atoms in this compound.
In one formula unit of [tex]\rm FeC_5O_5[/tex], the number of atoms of oxygen has been 5. Thus , option B is correct.
Formula unit has been the empirical representation of the chemical compound. The formula has been responsible to deliver the information about the number of atoms of each elements present in the sample.
The given compound has been [tex]\rm FeC_5O_5[/tex]. The formula has subscript with each element representing the number of atoms. The atoms of each element has been:
Iron = 1Carbon = 5Oxygen = 5The number of atoms of oxygen present in one formula unit of [tex]\rm FeC_5O_5[/tex] has been 5. Thus , option B is correct.
For more information about the formula unit, refer to the link:
https://brainly.com/question/19293051
What happen when a piece of sodium is exposed in air?
Answer:
I literally got this from google.
Explanation:
In ordinary air, sodium metal reacts to form a sodium hydroxide film, which can rapidly absorb carbon dioxide from the air, forming sodium bicarbonate. ... In a comparatively dry atmosphere, sodium burns quietly, giving off a dense white caustic smoke, which can cause choking and coughing.
Happy almost Halloween! :)
() What volume of 0.20 M NaCl(aq) contains 10.0 g of NaCl (molar mass 58 g/mol)?
Volume can be calculated by using division calculation between Molarity and number of moles. The volume of 0.20 M NaCl(aq) containing 10.0 g of NaCl is 0.86L.
What is molarity?
Molarity can be calculated by dividing number of moles of solute by volume of solution in liter. Molarity is affected by temperature. Its unit is mole/litre. It measure the concentration of any solute in a solution.
Other concentration terms are molality, normality and mole fraction. Molarity can be used to find out the ionic strength of any solution.
Mathematically,
Molarity= number of moles of solute÷volume of solution in litre
Where,
moles= given weight÷by molecular weight
= 10/ 58
Substituting values in equation 1
volume=10÷(58×0.20)
volume= 10÷11.6
volume=0.86L
Therefore, The volume of 0.20 M NaCl(aq) containing 10.0 g of NaCl is 0.86L.
Learn more about the molarity, here:
https://brainly.com/question/16727614
#SPJ2
The idea that the earth is divided into a number of small plates that float on the mantle and slide,collide,and slip past each other. Law or Theories
Answer:
Theories
Explanation:
It is theories because it was a generalistee abstract or thinking generalising the principle of fact about Earth tectonic plates ,it was formulated and concluded as plate tectonic theories after many findings. The theories conclude that the Earth has an outer layer called lithosphere and lies overly a plastic layer called asthenosphere. The lithosphere is divided into several plates and they move close to each other where they diverge, converge or slip over one another.
the isotopes of an elements have the same masse
Answer:
True
Explanation:
But have different neutrons
