Answer:
7.35 to 7.45
Explanation:
According to healthline.com, the average pH of blood is 7.35 to 7.45.
what makes an element reactive
Answer:
The number of electrons in the outermost shell of an atom determines its reactivity.
Explanation:
Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation:
Which of the four models represents a solid
Answer:
is there an image
Explanation:
* 20 POINTS
A ________ is made of two or more elements chemically combined.
a.
alloy
b.
mixture
c.
element
d.
compound
Answer:
Compound is the answer
is sugar an element or a compound
Answer:
it is a compound
Explanation: i have it on a test
2.56 g of hydrogen reacts completely with 20.32 g of oxygen
to form X g of water. X = g
Answer:
Mass of water produced is 22.86 g.
Explanation:
Given data:
Mass of hydrogen = 2.56 g
Mass of oxygen = 20.32 g
Mass of water = ?
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 20.32 g/ 32 g/mol
Number of moles = 0.635 mol
Number of moles of hydrogen:
Number of moles = mass/ molar mass
Number of moles = 2.56 g/ 2 g/mol
Number of moles = 1.28 mol
Now we will compare the moles of water with oxygen and hydrogen.
O₂ : H₂O
1 : 2
0.635 ; 2×0.635 = 1.27
H₂ : H₂O
2 : 2
1.28 : 1.28
The number of moles of water produced by oxygen are less thus it will be limiting reactant.
Mass of water produced:
Mass = number of moles × molar mass
Mass = 1.27 × 18 g/mol
Mass = 22.86 g
Answer:
22.88
Explanation:
correct have a g'day mate
A chemist needs to create a series of standard Cu2+(aq) solutions for an absorbance experiment. For the first standard, he uses a pipet to transfer 10.00 mL of a 2.61 M Cu2+(aq) stock solution to a 250.0 mL volumetric flask, and he adds enough water to dilute to the mark. He then uses a second pipet to transfer 10.00 mL of the second solution to a 100.0 mL volumetric flask, and he adds enough water to dilute to the mark. Calculate the concentration of the Cu2+(aq) solution in the 100.0 mL volumetric flask. concentration: M
Answer:
0.01 M
Explanation:
The chemist is performing a serial dilution in order tyo obtain the calibration curve for the instrument.
First we must obtain the concentration of the solution in the 250ml flask from
C1V1 = C2V2
Where;
C1 = concentration of the stock solution
V1 = volume of the stock solution
C2 = concentration of the diluted solution
V2= volume of the diluted solution
2.61 × 10 = C2 × 250
C2 = 2.61 × 10/250
C2 = 0.1 M
Hence for solution in 100ml flask;
0.1 × 10 = C2 × 100
C2 = 0.1 × 10/100
C2 = 0.01 M
the commands given in nucleus are throughout the cell by the
A.endoplamic reticulum
B.Flagella
C.mitochondria
D.golgi bodies
E.vacuole
Answer:
A.endoplamic reticulum
Explanation:
The endoplamic reticulum is an important organelle in protein synthesis. The nucleus contains DNA, which is the template for transcription of mRNA. mRNA acts as a message, which leaves the nucleus to become translated into proteins.
The endoplasmic reticulum is important in the synthesis, folding, and modification of proteins.
What is the volume of 12.0 M NaOH needed to prepare 5.00 L of a 2.50 M NaOH solution? What volume of water (solvent) is required to make this dilution? Please show work
Answer:
Approximately [tex]1.04\; \rm L[/tex] of the [tex]12.0\; \rm M[/tex] [tex]\rm NaOH[/tex] solution is needed. Approximately another [tex]3.96\; \rm L[/tex] of water will also be required.
Assumption: the volume of these [tex]\rm NaOH[/tex] solutions does not depend on the quantity of [tex]\rm NaOH\![/tex] (the solute) that each of them contain.
Explanation:
Calculate the number of moles of [tex]\rm NaOH[/tex] formula units in that [tex]5.00\; \rm L[/tex] of [tex]2.50\; \rm M[/tex] [tex]\rm NaOH\![/tex] solution:
[tex]n(\mathrm{NaOH}) = c\cdot V = 5.00\; \rm L \times 2.50\; \rm mol \cdot L^{-1} = 12.5\; \rm mol[/tex].
Calculate the volume of a [tex]12.0\; \rm M[/tex] [tex]\rm NaOH[/tex] with that many [tex]\rm NaOH\![/tex] formula units:
[tex]\displaystyle V = \frac{n}{c} = \frac{12.5\;\rm mol}{12.0\; \rm mol \cdot L^{-1}}\approx 1.04\;\rm L[/tex].
That should be the volume of the [tex]12.0\; \rm M[/tex] [tex]\rm NaOH[/tex] solution needed to prepare that [tex]5.00\; \rm L[/tex] of [tex]2.50\; \rm M[/tex] [tex]\rm NaOH\![/tex] solution. However, [tex]1.04\; \rm L[/tex] corresponds to only about one-fifth the volume of a [tex]5.00\; \rm L\![/tex] solution. The difference in volume should be filled with pure water:
[tex]\begin{aligned}V(\text{water}) &\approx 5.00\; \rm L - 1.04\; \rm L = 3.96\; \rm L\end{aligned}[/tex].
The total energy in an isolated system is conserved.
True or false?
Answer:
true
Explanation:
How many atoms of copper are in 0.137g of copper?
the object in question 1 has a mass of 21.535g. what metal is the cylinder most likely made of? why? pls help asap!!
Answer:
Aluminium
Explanation:
From the question given above, the following data were obtained:
Diameter (d) = 1.25 cm
Height (h) = 6.48 cm
Volume (V) of cylindrical=.?
Mass (m) of cylindrical object = 21.535 g
Density of the cylindrical object =..?
Next, we shall determine the radius of the cylindrical object. This is illustrated below:
Diameter (d) = 1.25 cm
Radius (r) =?
r = d/2
r = 1.25/2
Radius (r) = 0.625 cm
Next, we shall determine the volume of the cylindrical object. This can be obtained as follow:
Height (h) = 6.48 cm
Radius (r) = 0.625 cm
Pi (π) = 3.14
Volume (V) of cylindrical=.?
V = πr²h
V = 3.14 × 0.625² × 6.48
V = 7.948 cm³
Recall:
1 cm³ = 1 mL
Therefore
7.948 cm³ = 7.948 mL
Thus, the volume of the cylindrical object is 7.948 mL
Finally, we shall determine the metal in which the cylindrical object is made up of by calculating the density of the cylindrical object. This can be obtained as follow:
Mass (m) of cylindrical object = 21.535 g
Volume of the cylindrical object = 7.948 mL
Density of cylindrical object =?
Density = mass /volume
Density = 21.535 / 7.948
Density of cylindrical object = 2.7 g/mL
Comparing the density of the cylindrical object (i.e 2.7 g/mL) with those given in the table in the question, the cylindrical object is made of aluminium since they have the same density.