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it's medical
22
Which of the following statements about acids and alkalis is TRUE?
(1 Point)
ammonium hydroxide is alkaline due to the presence of OH+ ions
hydroxide ions make sodium hydroxide solution alkaline
O hydrochloric acid solution is acidic because it contains hydride ions
Answer:
''hydroxide ions make sodium hydroxide solution alkaline'' is true.
Explanation:
In the first sentence, OH+ ions is incorrect. It has to be OH- ions.
In the last sentence, hydride ions(H-ions) is incorrect. It has to be hydrogen ions(H+ ions).
how do I find lattice energy with the overall heat of dissolution of aluminum sulfate?
Al2(SO4)3=> 2Al³(aq)+ + 3SO4²- (aq) + 318kJ
Explanation:
you can use Born-Lande equation,
U=-(A×e^2×Z+ ×Z- ×N)\r ×(1-1/n)
here,U=lattice energy
A=madelung constant
n=Born exponent(depends on repulsion between ion)
e=charge of electron
Z+,Z-=charge of cation and anion
r=distance between cation and its neighbour anion in
space lattice
How many moles of steam are produced when 5.74 moles of octane (C8H18) react?
Calculate the volume which 1.00 mole of a gas occupies at STP.
Answer:
22.4 L
Explanation:
A gas at STP will possess the following;
Pressure (P) = 1 atm
Temperature (T) = 273K
General gas constant (R) = 0.0821 Latm/molK
Using the general gas law formula to calculate the volume a gas of 1 mol will contain;
PV = nRT
V = nRT/P
V = 1 × 0.0821 × 273 ÷ 1
V = 22.41/1
V = 22.4 litres
What is the pH of a buffer solution prepared by mixing 20.0 mL of 0.0800 molL−1NaOH with 20.0 mL of 0.130 molL−1 cacodylic acid?
Answer:
pH = 6.20
Explanation:
The pKa of cacodylic acid is 6.
To solve this question we must use Henderson-Hasselbalch equation:
pH = pKa +log [A⁻] / [HA]
Where pKa is the pKa of the weak acid = 6
And [] could be taken as the moles of A⁻ the conjugate base, and HA, the weak acid.
The moles of the NaOH added to the solution of the weak acid are = Moles A⁻
And moles HA = Initial moles HA - Moles NaOH added
Initial moles HA:
0.0200L * (0.130mol / L) = 0.00260 moles
Moles NaOH:
0.0200L * (0.0800mol / L) = 0.00160 moles = [A⁻]
Moles HA =
0.00260 moles - 0.00160 moles = 0.00100 moles = [HA]
pH = 6 +log [0.00160 moles] / [0.00100 moles]
pH = 6.20The pH of the resulting solution is 1.6.
Let cacodylic acid be HA, mixing cacodylic acid and NaOH, the following occurs;
HA(aq) + NaOH(aq) ------> NaA(aq) + H2O(l)
Number of moles of NaOH = 0.0800 molL−1 × 20.0/1000 = 0.0016 moles
Number of moles of HA = 20.0/1000 × 0.130 = 0.0026 moles
We can see that the HA is in excess, Number of moles of excess acid =
0.0026 - 0.0016 = 0.001 moles
Total volume of solution = 20.0 mL + 20.0 mL = 40 mL or 0.004 L
Molarity of excess acid = 0.001 moles/0.004 L = 0.025 M
pH = -log[H^+]
pH = -log[0.025 M]
pH = 1.6
Learn more: https://brainly.com/question/2510654
A balanced chemical equation takes into account the theory that:
a. Compounds and elements remain unchanged in a chemical reaction
b. Atoms are neither created nor destroyed in a chemical reaction
c. The total mass always increases during a chemical reaction
d. The mass of any gases involved can be ignored.
Which is correct?
Answer:
b. Atoms are neither created nor destroyed in a chemical reaction
Explanation:
B is correct, because the law of conservation of mass tells us that during a chemical reaction, there is no net gain or loss of mass. Mass comes from the atoms themselves that are participating in the reaction, so there is no gain or loss (creation or destruction) of atoms.
The primary role of ATP is to _______ by transferring a phosphate group to a molecule and forming ADP.
A
provide energy for cellular work
B)
produce heat energy
C)
reduce the activation energy of a reaction
D)
take energy from cellular work
Answer:
A) provide energy for cellular work
Explanation:
The Adenosine triphosphate (ATP) molecule is the nucleotide known in biochemistry as the "molecular currency" of intracellular energy transfer; that is, ATP is able to store and transport chemical energy within cells. ATP also plays an important role in the synthesis of nucleic acids.
ATP always GIVES ENERGY
2) You start with 3.8 x 1021 gold atoms, how many moles is this?
Answer:
0.0063mol
Explanation:
Number of moles (n) in a substance can be calculated by dividing the number of atoms (nA) of that substance by Avagadro's number i.e. 6.02 × 10^23. That is; n = nA ÷ 6.02 × 10^23
1 mol of Gold = 6.02 × 10^23 atoms
Therefore, 3.8 x 10^21 atoms of Gold will be;
3.8 x 10^21 ÷ 6.02 × 10^23
= 3.8 ÷ 6.02 × 10^ (21 - 23)
= 0.6312 × 10^-2
= 0.0063mol of Gold
Calculate the change in heat (Q) that occurs when 38.68grams of steam at 304°C cools to liquid water at 197°C. (cp = 4.184 J/g°C)
Answer:
Change in heat (Q) = -1.7316 x 10⁴
Explanation:
Given:
Mass m = 38.68 g
Change in temperature Δt = (197-304) = -107°C
Specific heat C = 4.184 J/g°C
Find:
Change in heat (Q)
Computation:
Change in heat (Q) = (C)(m)(Δt)
Change in heat (Q) = (4.184)(38.68)(-107)
Change in heat (Q) = -1.7316 x 10⁴
5. Keratin and collagen are examples of *
li
Answer:
Structural proteins
Explanation:
Glad I could Help Pls Brainliest
What is the answer?
Answer:
Option A
Explanation:
The atomic number is the number of protons in the nucleus of an atom.
how do you balance sulfur + fluoride = sulfur hexafluoride?
S + F2 >>> SF6
HELP PLEASE ||Suppose you add water to a 6 g of sugar to make a solution with a concentration of 3 g/L. What is the total volume of the solution?
Answer:
2 L
Explanation:
Divide the mass by the concentration to find the volume.
(6 g)/(3g/L) = 2 L
According to the concept of solubility, in order to make solution of sugar the total volume of solution is 2 g/L.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
In order to calculate total volume of solution divide mass/ concentration that is 6/3=2 g/L.
Thus, the total volume of the solution is 2 g/L.
Learn more about solubility,here:
https://brainly.com/question/29589228
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4 Al + 3 O₂ --> 2 Al2Ol₃ Given 6 moles of aluminum, how many grams of aluminum oxide will be produced?
Answer:
305.88 g
Explanation:
4 Al + 3 O₂ → 2 Al₂O₃
First, we convert 6 moles of aluminum (Al) into moles of aluminum oxide (Al₂O₃), using the stoichiometric coefficients:
6 mol Al * [tex]\frac{2molAl_2O_3}{4molAl}[/tex] = 3 mol Al₂O₃
Finally we convert 3 moles of aluminum oxide into grams, using its molar mass:
3 mol Al₂O₃ * 101.96 g/mol = 305.88 g
Chemical equations consist of the chemical formulas of the reactants on the right
and the chemical formulas of the products on the left.
True
False
which image of earth is more recent?
Answer:
b
Explanation:
Answer:
2
Explanation:
its has more space now cause of The to contemplates
the equation of 3times x is 38
Answer is 38/3 or 12.67
3x=38
x=38/3
therefore answer is the one mentioned above
true or false. a less reactive halogen will displace a more reactive halogen from an aqueous solution of its salt.
Answer:
I think the answer is false
Is this balanced ?CsH12 + 702 → 5 CO2 + 6H2O
Answer:
Nope
Explanation:
Answer: nope, it should be : C5H12 + 8O2 → 5CO2 + 6H2O
give an example of competition in an ecosystem
hbzjaj
Explanation:
competition for food
please help! Question is on the bottom
Hockey is a sport in which players use hockey sticks to push a puck across smooth ice. At practice one day, three different-colored hockey pucks were sliding on the ice. The green hockey puck has less mass than the black and purple hockey pucks, which have the same mass. A player hit each hockey puck with a stick, but not from the same direction. Use the information in the diagram to answer.
Which puck(s) experienced the strongest force when hit? How do you know?
Answer:
The purple hockey puck; it takes a stronger force to slow down a more massive object than to speed it up.
Explanation:
Hope this helps! :) Plz mark as brainliest if u can!
what is change in science
Answer:
Scientific change is: "Any change in the scientific mosaic, i.e. a transition from one accepted theory to another or from one employed method to another. "
Explanation:
What type of reaction occurs when potassium iodide is combined with lead (II) nitrate?
A. single replacement
b. double replacement
c. synthesis
d. combustion
Answer:
double replacement occurs
how do you make fried chicken im white and don't know how to season
Answer:
lol you use batter use flour salt pepper thats what gives it the fried and crispy taste
Explanation:
Name two chemical used to disinfect water
Answer:
chlorine and I think maybe sulphur. but check the internet
Answer:
chlorine I think so . sorry if it ain't the right answer
please help as fast as u can
Answer:D
D
DDD
DDDDDDDDDD
Explanation:
Answer:
C. 1 and 3 only
Explanation:
In this element representation';
The superscript (23) s the mass number. Mass Number = Protons + Neutrons
-The subscript (11) is the atomic number.
Atomic Number = Protons
This means;
Number of Protons = 11
Number of Neutrons = 23 - 11 = 12
Number of electrons = 11 (Since it is a neutral atom)
Also sodium belongs to group 1 hence number of outer electrons = 1
The correct option is;
C. 1 and 3 only
The formula for photosynthesis is shown.
64,0 + 600, → CH2+ 60,
What are the reactants of photosynthesis? (7.5A)
A.water and carbon dioxide
B.
oxygen and water
C.
glucose and oxygen
D.carbon dioxide and glucose
Judge Joe is looking over a list of expert witnesses that must be summoned to court. Which one of the following actions would he take pretrial to ensure they appear? A. Issue an arrest warrant. B. Conduct a jury poll. C. Send out subpoenas. D. Interpret case law.
A swimmer is moving at a speed of 2.0 meters/second. How long will it take for the swimmer to go 100 meters?