Answer:
Density = 11.4 g/cm³
Explanation:
Given data:
Density of lead = ?
Height of lead bar = 0.500 cm
Width of lead bar = 1.55 cm
Length of lead bar = 25.00 cm
Mass of lead bar = 220.9 g
Solution:
Density = mass/ volume
Volume of bar = length × width × height
Volume of bar = 25.00 cm × 1.55 cm × 0.500 cm
Volume of bar = 19.4 cm³
Density of bar:
Density = 220.9 g/ 19.4 cm³
Density = 11.4 g/cm³
A chemist dissolves of pure potassium hydroxide in enough water to make up of solution. Calculate the pH of the solution. (The temperature of the solution is .) Be sure your answer has the correct number of significant digits.
Answer:
12.99
Explanation:
A chemist dissolves 716. mg of pure potassium hydroxide in enough water to make up 130. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Be sure your answer has the correct number of significant digits.
Step 1: Given data
Mass of KOH: 716. mg (0.716 g)Volume of the solution: 130. mL (0.130 L)Step 2: Calculate the moles corresponding to 0.716 g of KOH
The molar mass of KOH is 56.11 g/mol.
0.716 g × 1 mol/56.11 g = 0.0128 mol
Step 3: Calculate the molar concentration of KOH
[KOH] = 0.0128 mol/0.130 L = 0.0985 M
Step 4: Write the ionization reaction of KOH
KOH(aq) ⇒ K⁺(aq) + OH⁻(aq)
The molar ratio of KOH to OH⁻is 1:1. Then, [OH⁻] = 0.0985 M
Step 5: Calculate the pOH
We will use the following expression.
pOH = -log [OH⁻] = -log 0.0985 = 1.01
Step 6: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - pOH = 14 -1.01 = 12.99
When NH3(aq) is added to Cu2 (aq), a precipitate initially forms. Its formula is:
a. Cu(NH)3
b. Cu(NO3)2
c. Cu(OH)2
d. Cu(NH3)22
e. CuO
When NH₃(aq) is added to Cu₂(aq), a precipitate initially forms. Its formula is Cu(NH₃)². The correct option is d.
What is a chemical formula?A chemical formula is a representation of chemical elements and chemical compounds. The chemical letters are used to write the chemical formula. The charges if present is written by charges symbols like plus, minus.
The chemical reaction is
NH₃(aq) + Cu₂(aq) = Cu(NH₃)²
This is called a chemical reaction, which contains reactant on the left side and products on the right side. The precipitate that is formed is copper ammonia whole twice.
Precipitation is the solid crystals' substance that is come out at the surface of the liquid. It is collected in solid form, and it is called a precipitate.
Thus, the correct option is d. Cu(NH₃)².
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A chemist adds of a M calcium sulfate solution to a reaction flask. Calculate the mass in grams of calcium sulfate the chemist has added to the flask
Answer:
1.23 g
Explanation:
A chemist adds 1.55 L of a 0.00582 M calcium sulfate solution to a reaction flask. Calculate the mass in grams of calcium sulfate the chemist has added to the flask.
Step 1: Given data
Volume of the solution (V): 1.55 LMolar concentration of the solution (C): 0.00582 M (0.00582 mol/L)Step 2: Calculate the moles (n) of calcium sulfate added
We will use the following expression.
n = C × V
n = 0.00582 mol/L × 1.55 L
n = 0.00902 mol
Step 3: Calculate the mass corresponding to 0.00902 moles of calcium sulfate
The molar mass of calcium sulfate is 136.14 g/mol.
0.00902 mol × 136.14 g/mol = 1.23 g
Which describes a difference between cephalopods and gastropods?
Cephalopods have a water vascular system, and gastropods have an open circulatory system.
Cephalopods live only in ocean environments, and gastropods live in a variety of environments.
Cephalopods have a simple nervous system, and gastropods have a complex nervous system.
Cephalopods are the largest group of mollusks, and gastropods are the smallest group of mollusks. CAN SOMEONE PLZZZZ ANWER THIS I WILL GIVE U 15 PIONTS
Answer:
B
Explanation:
I took the test
Answer:
The correct answer is B
Explanation:
What are the products of the acid-base reaction of sodium carbonate with acetic acid?
Answer:
The mixture quickly foams up with carbon dioxide gas. If enough vinegar is used, all of the baking soda can be made to react and disappear into the vinegar solution. The reaction is: Sodium bicarbonate and acetic acid reacts to carbon dioxide, water and sodium acetate.
Explanation:
hope this helps
What is POH?
A. pH = log[OH-]
B. POH =[ht][OH-]
C. pOH = -log(OH)
D. pH = -log[H+]
Answer:
The answer is C
Explanation:
2.2.2: The pH Scale
pOH = -log[OH-]
Container A holds 717 mL of an ideal gas at 2.80 atm. Container B holds 174 mL of a different ideal gas at 4.30 atm. Container A and container B are glass spheres connnected by a tube with a stopcock. Container A is larger than container B. If the gases are allowed to mix together, what is the resulting pressure
Answer:
3.09 atm
Explanation:
Given that:
Volume of container A = 717 mL
Pressure of container A = 2.80 atm
Volume of container B = 174 mL
Pressure of container B = 4.30 atm
Now, if the valve are being removed and the gases are allowed to mix together; then
The total final pressure can be calculated by using the formula:
[tex]P_f = \dfrac{P_AVA+P_BV_B}{V_A+V_B}[/tex]
[tex]P_f = \dfrac{2.80*717+4.30*174}{717+174}[/tex]
[tex]P_f = \dfrac{2007.6+748.2}{891}[/tex]
[tex]P_f = \dfrac{2755.8}{891}[/tex]
[tex]\mathbf{P_f =3.09 \ atm}[/tex]
The absence of the intermolecular attraction between the atoms or molecules is called an ideal gas. The pressure of the resultant mixture is 3.09 atm.
What is the relation between pressure and volume?The relationship between the pressure and the volume of the gas is given by Boyle's law which states the inverse proportionality relation with the volume.
Given,
The volume of container A = 717 mL
The volume of container B = 174 mL
The pressure of container A = 2.80 atm
The pressure of container B = 4.30 atm
The total final pressure of the ideal gas of the mixture is calculated by:
[tex]\begin{aligned} \rm P_{f} &= \rm \dfrac{P_{A}V_{A}+ P_{B}V_{B}}{V_{A}+V_{B}}\\\\&= \dfrac{2007.6 +748.2}{891}\\\\&= 3.09 \;\rm atm\end{aligned}[/tex]
Therefore, the total pressure of the mixture is 3.09 atm.
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Question 3 (1 point)
Consider the following unbalanced chemical equation representing the combustion of methane, yielding carbon dioxide and water.
CH4 + O2 --> CO2 + H20
If you had burned 800 g of methane, how many moles of Carbon dioxide would be produced?
A)122.22
B)8
C)2200
D)100
E)670
F)750
G)50
Answer:
Im pretty sure its B
Explanation:
Answer:
G) 50 mol
Explanation:
Given data:
Mass of methane = 800 g
Number of moles of CO₂ produced = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of methane:
Number of moles = mass/molar mass
Number of moles = 800 g/ 16 g/mol
Number of moles = 50 mol
Now we will compare the moles of methane and carbon dioxide.
CH₄ : CO₂
1 : 1
50 : 50
Explain the concept of “Happy Atoms” as it relates to why atoms bond together.
Answer:
I think this means that they always compatible so th er e basically friends and they stick together. c: hope I helped
Why does solid water (ice) float when placed in liquid water? *
Ice does not float in liquid water.
Ice is less dense than liquid water.
Ice is more dense than liquid water.
The densities of liquid water and ice are the same .
Answer:
Ice is less dense than water.
A scientist observes several different fossils in a
rock layer. Based on this observation, which is
the best conclusion?
A. The fossils are composed of lava that cooled
around several organisms.
B. The fossils formed about the same time as the
rock layer in which they were found.
C. The fossils formed after heat and pressure
changed the type of rock in the rock layer.
D. The fossils are composed of the same material
as the organisms from which they formed.
A scientist observes several different fossils in a
rock layer. Based on this observation, which is
the best conclusion?
Answer:A. The fossils are composed of lava that cooled
A. The fossils are composed of lava that cooledaround several organisms.
B. The fossils formed about the same time as the rock layer in which they were found.
Explanation:That's the right answer but you can choose one.
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