Answer:
Weigh the empty crucible, and then weigh into it between 2 g and 3 g of hydrated copper(II) sulphate. Record all weighings accurate to the nearest 0.01 g.
Support the crucible securely in the pipe-clay triangle on the tripod over the Bunsen burner.
Heat the crucible and contents, gently at first, over a medium Bunsen flame, so that the water of crystallisation is driven off steadily. The blue colour of the hydrated compound should gradually fade to the greyish-white of anhydrous copper(II) sulfate. Avoid over-heating, which may cause further decomposition, and stop heating immediately if the colour starts to blacken. If over-heated, toxic or corrosive fumes may be evolved. A total heating time of about 10 minutes should be enough.
Allow the crucible and contents to cool. The tongs may be used to move the hot crucible from the hot pipe-clay triangle onto the heat resistant mat where it should cool more rapidly.
Re-weigh the crucible and contents once cold.
Calculation:
Calculate the molar masses of H2O and CuSO4 (Relative atomic masses: H=1, O=16, S=32, Cu=64)
Calculate the mass of water driven off, and the mass of anhydrous copper(II) sulfate formed in your experiment
Calculate the number of moles of anhydrous copper(II) sulfate formed
Calculate the number of moles of water driven off
Calculate how many moles of water would have been driven off if 1 mole of anhydrous copper(II) sulfate had been formed
Write down the formula for hydrated copper(II) sulfate.
#*#*SHOW FULLSCREEN*#*#
Explanation:
How many moles of oxygen are needed for the complete combustion of 29.2 grams of acetylene?
Moles of Oxygen= 2.8075 moles
Further explanationGiven
29.2 grams of acetylene
Required
moles of Oxygen
Solution
Reaction(Combustion of Acetylene) :
2 C₂H₂ (g) + 5 O₂ (g) ⇒ 4CO₂ (g) + 2H₂O (g)
Mol of Acetylene :
= mass : MW Acetylene
= 29.2 g : 26 g/mol
= 1.123
From equation, mol ratio of Acetylene(C₂H₂) : O₂ = 2 : 5, so mol O₂ :
= 5/2 x mol C₂H₂
= 5/2 x 1.123
= 2.8075 moles
The asthenosphere is the part of the upper mantle just below the lithosphere that os involved in the plate tectonic movement anf isostatic adjustments during as the ice age
Answer:C
Explanation:
Answer:
It's B I promise you
6. Which example has BOTH ionic and covalent bonds? *
Answer:
It’s either A or D buttttt probably d
Explanation:
Your friend cuts his sandwiches in half diagonally because then he gets twice as much
food! What is wrong with his reasoning?
Answer:
It is still one sandwich it doesn't become twice the size just because you cut it, it just becomes one sandwich cut into two
Explanation:
A gas with a volume of 2 L at 25°C is placed into a container that is 4 L. What is the new temperature of the gas?
Given :
A gas with a volume of 2 L at 25°C is placed into a container that is 4 L.
To Find :
The new temperature of the gas.
Solution :
Since, their is no information regarding pressure. We will assume that pressure is constant.
Now, we know when at constant pressure, volume is directly proportional to volume.
[tex]\dfrac{V_1}{V_2}=\dfrac{T_1}{T_2}\\\\\dfrac{2}{4} = \dfrac{25 + 273 }{x}\\\\x = 2 \times ( 25 + 273 )\\\\x = 596\ K[/tex]
Therefore, the new temperature of the gas is 596 - 273 K = 323 K.
How much current is drawn by a 40-W bulb in a 120-V circuit?
as time goes on specimens in the fossil record become more
a-complex
b-common
c-confusing
d-simple
Answer:
complex
Explanation:
becaause it fits in the words equation I hoped i helped
I'd love some help please thank you
Answer:
the answer would be B
Explanation:
The move vigorously it is the higher the reactivity so if you put it in order the answer would be B
Marcellus is using distillation to obtain pure water from seawater. His apparatus is shown below. Put each label in the correct place on the diagram.
Answer:
I hope this photo can help you.
Question 3, please help!! 10 points
Answer:
0.68 centiseconds
Explanation:
I looked it up
Answer:
The person above is correct 6800 converted to centiseconds is .68
Explanation:
you have to divide x by 10000 to convert it into centiseconds
in this case x=6800
6800÷10000= 0.68
How many strontium atoms would have a mass of 1.45 grams ?
In general, what is the trend in atomic radius as atomic number increases in a vertical column on the periodic table?
Answer:
In general, the trend in atomic radius as the atomic number in a vertical column of the periodic table increases is to increase.
Explanation:
The atomic radius represents the distance between the nucleus and the valence shell (that is, the outermost). By means of the atomic radius it is possible to determine the size of the atom.
In groups, the atomic radius increases with the atomic number, that is, down a column. This is because as the atomic number of the elements in a group increases, the number of occupied levels increases, while the effective nuclear charge on the outermost electron is the same. Consequently, the atomic radius increases.
In other words, when you go down in a group (column) of the periodic table, the effective nuclear charge increases, but the number of electrons added with respect to the previous element, the same group increases in a complete shell. The effect of adding new electronic shells is predominant, so they are increasingly distant from the atomic nucleus and the atomic radius is greater when you go down in a group.
So the increase in atomic radius as you go down in a group is due to the increase in electron shells.
C.
[2]
Name another chemical which can be used to test for the present of water and state the
colour change.
Answer:
See explanation
Explanation:
There are two chemicals commonly used to test for water. They are;
CuSO4: Anhydrous CuSO4 is white in colour, when it absorbs moisture, its colour changes from white to blue.
CoCl2: Anhydrous CoCl2 is blue in colour. when it absorbs moisture, its colour changes from blue to pink.
Please help me, Thank you!
Answer:
amount of charge
Explanation:
Oxygen and sulfur are both in Group 16, which means they have a -2 charge. They have two more electrons than protons, making the charge of the ion negative.
Hope that helps.
what is an example of a chemical change that occurs during weathering
Answer:
Hydrolysis is a chemical wheathering process that may affect silicates and carbonates minerals. an example of such a reaction in which water reacts with a silicates minerals is the following: Mg2SiO4 + 4H2O ⇄ 2 Mg(OH)2 + H4SiO. olivine (forsterite) + water ⇄ brucite + silicic acid.
Explanation:
A student takes four samples of a white crystalline solid and places each in a well plate. On top of each sample, she carefully places 20 drops of clear mystery liquids A, B, C and D. Her results for each well are as follows:
Liquid A: The solid dissolves quickly.
Liquid B: The solid appears unchanged.
Liquid C: A brownish colored liquid is produced.
Liquid D: Fizzing occurs and the well becomes warmer.
In which well does a PHYSICAL change occur?
Answer:
A
Explanation:
Sorry if wrong
Answer:
Liquid B: The solid appears unchanged.
Explanation:
A is a chemical change, because the solid dissolves away.
C is a chemical change, because the solid changes color.
D is a chemical change, because fizzing occurs.
B is the only solid that seems to remain the same.
5.0g of copper is heated from 20 Celsius to 80 Celsius. How much energy it was used to heat Cu? (Specific heat capacity of Cu is 0.092 cal/g)
Answer:
the energy used to heat Cu is 27.6 Cal
Explanation:
given data
mass m = 5 g
Specific heat capacity of Cu = 0.092 cal/g
temperature T2 = 80 Celsius
temperature T1 = 20 Celsius
solution
we get here energy used to heat Cu that is express as
Q = m × c × ΔT ....................1
so here m = mass and c = specific heat capacity
and ΔT = T2 - T1
so put value in eq 1
Q = 5 × 0.092 × (80 - 20)
Q = 27.6 Cal
so that the energy used to heat Cu is 27.6 Cal
What does x mean- like person x person?
Answer:
× = and
Explanation:
person and person
*Fill in the blank about the periodic table*
Atomic number equals the number of ______ or ______
Atomic mass equals the number of _____ + ______
Atomic number equals the number of protons or electrons. Atomic mass equals the number of protons and neutrons
I've been stuck with this for like an hour, please help.
A 100 gram sample of HG is equal to how many moles of the metal?
Explanation:
Molar mass of Hg = 200.59g/mol.
Therefore Moles = Mass / Molar mass
= 100g / (200.59g/mol) = 0.499mol.
i need help with these. its balancing. the blank spaces are where u put the numbers. and the stuff on the sidd is how u show work. i got lost and dont know what comes next
How many moles of nitrogen are in 9.82x10^23 formula units of nitrogen? Please show work!
Answer:
1.63 mols
Explanation:
to convert mols to formula unit, or formula unit to mols, u need the avagadros number which is 6.022*10^23 and the number of mols/formula units
so since the given is formula units, u just have to divide the number by 6.022*10^23 to get the amount of mols
9.82*10^23 / (6.022*10^23) = 1.63 mols
*be careful for sig figs
Please help me, Thank you!
Answer:
Fe³⁺
Explanation:
When Fe²⁺ loses an electron, it becomes an Fe³⁺ ion.
The loss of an electron in an atom makes the atom becomes positively charged. Further losing electrons makes the atom more positive.
For the given ion;
Fe²⁺ if it loses an electron more, it becomes Fe³⁺.
The expression is given as:
Fe²⁺ → Fe³⁺ + e⁻
1 Produce a time line for the formation of the atmosphere,
starting with the formation of the Earth 4500 million years ago.
2 Use your research skills to find out:
a more about the ozone hole problem
b what precautions are necessary to prevent an increase in
skin cancers.
Pls help!!!!!
Answer:
1) Well I think you need to research that in G00GLE
Explanation:
2 answer
a) The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth's surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage.
b) Seek the shade, especially between 10 AM and 4 PM.
Don't get sunburned.
Avoid tanning, and never use UV tanning beds.
Cover up with clothing, including a broad-brimmed hat and UV-blocking sunglasses.
Use a broad-spectrum (UVA/UVB) sunscreen with an SPF of 15 or higher every day.
PLEASE HELP ASAP
Which letter represents the moles of a formula in the reaction?
C
E
D
A
B
Answer: b should be the answer just took this test
Explanation:
What is the movement of matter due to density differences called?
A a convection current
B a pressure belt
C a climate cycle
D an ocean current
Answer:
A convention current.
Explanation:
the difference between Ionic and Covalent bonding.
According to kinetic theory, all matter is made up of small particles. The particles are constantly
moving
Diagram 1 shows how the particles may be arranged in a solid.
Diagram 1
(a)
One kilogram of a gas has a much larger volume than one kilogram of a solid
Use kinetic theory to explain why.
Enter your answer
Answer:
(a) there are strong forces (of attraction) between the particles in a solid
accept molecules / atoms for particles throughout
accept bonds for forces
1
(holding) the particles close together
particles in a solid are less spread out is insufficient
1
or
(holding) the particles in a fixed pattern / positions
but in a gas the forces between the particles are negligible
accept very small / zero for negligible
accept bonds for forces
1
so the particles spread out (to fill their container)
accept particles are not close together
gas particles are not in a fixed position is insufficient
Explanation:
Bill is pushing a box with 10 N of force to the left, while Alice is pushing the box with 30 N of force to the right. What is the net force?
Answer:
Fnet = 20 Newton
Explanation:
Let the force applied by Brian be Fb.
Let the force applied by Alice be Fa.
Given the following data;
Force, Fb = 10N
Force, Fa = 30N
To find the net force, Fnet;
Net force can be defined as the vector sum of all the forces acting on a body or an object i.e the sum of all forces acting simultaneously on a body or an object.
Mathematically, net force is given by the formula;
[tex] Fnet = Fapp + Fg[/tex]
Where;
Fnet is the net force Fapp is the applied forceFg is the force due to gravitationSince the two force applied to the box are acting in opposite direction, we would subtract their values to find the net force.
Fnet = Fa - Fb
Fnet = 30 - 10
Fnet = 20 Newton
A client is to recieve 2.00g of a drug. The drug comes on a solution that has 500 mg per 5.0 mL. Each vial contains 10 milliliters. How many vials do you need?
Answer:
2 vials
Explanation:
The concentration (C) of the drug in the solution is:
C= 500 mg/5 mL = 100 mg/mL
Each vial with a volume (V) of 10 mL, contains the following mass of drug:
V= 10 mL ⇒ C x V = 100 mg/mL x 10 mL = 1000 mg
As you need 2.00 g, and 1 gram is equivalent to 1000 mg, the mass needed is 2.00 g x 1000 mg/1 g = 2000 mg
Thus, you have to divide the mass you need into the mass of each vial:
(2000 mg)/(1000 mg/vial) = 2 vials
Therefore, you need 2 vials.
