Answer:
1.89 × 10³ J
Explanation:
Step 1: Given data
Heat of fusion (ΔH°fus): 126 J/gMass of the sample (m): 15.0 gStep 2: Calculate the heat (Q) required to melt the sample
The fusion is the phase change from solid to liquid. We can calculate the heat required for the fusion of the sample using the following expression.
Q = ΔH°fus × m
Q = 126 J/g × 15.0 g
Q = 1.89 × 10³ J
When a mixture of rock pieces, salt and water is filtered, what will be found as the filtrate and what will be found as the residue
Answer:
Filtrate: Mixture of salt and water.
Residue: rock pieces
Answer:
Salt solution will be the filtrate
and the rock pieces will be the residue.
Explanation:
This is because salt is soluble in water and hence
it cannot be filtered out of water giving as a salt solution as the filtrate and since the rock pieces are not soluble in water they are left out and they become the residue.
The answer to the problem: (2.1x103) x (4x105) = _____, written to the correct number of significant digits and in scientific notation is:
!! Carat denotes to the power. Example: 10^4 is 104 !!
Answer: The answer is [tex]8.4\times 10^8[/tex]
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
Thus for product of [tex](2.1\times 10^3)\times (4\times 10^5)[/tex]
In this problem, 2.1has 2 significant figures and 4 is an exact number with infinite significant digits thus product will have the least number of significant figures which is 2. So, the answer will be in 2 significant figures.
Therefore, the answer is [tex]8.4\times 10^8[/tex]
The waste product of nuclear energy which is a possible pollutant is:
A.smoke
B.hot air
C.radiation
D.heat pollution to lake
Answer:
CCCCCCC
Explanation:
Answer:
C. radiation
Explanation:
the possible pollutant is radiation because nuclear energy causes ; electromagnetic waves are radio waves, light, infrared rays, UV rays, X rays, Gamma rays. These are well known and are used extensively in the fields of communications, industry, medicine and research.
Radiation is a term given for waves caused by electromagnetism and high energy particles .Radioactive substances have High energy particles which are tiny bits of matter that are made to move at high speeds releasing nuclear radiation. There are about 50 naturally occurring radioactive substances and More than 2000 man-made ones. There are three kinds of radioactive radiation – alpha particles, beta particles and gamma radiation.
Which of the following is a chemical property?
O volume
O flammability
O color
O weight
Answer:
your answer is flammability
What mass of carbon monoxide gas (CO) would occupy a volume of 4.30 L at STP? Explain how you got the answer.
Answer:
5.38 g of CO.
Explanation:
From the question given above, the following data were obtained:
Volume of CO = 4.3 L
Mass of CO =?
Next, we shall determine the number of mole of CO that occupied 4.3 L at STP. This can be obtained as follow:
Recall = 1 mole of any gas occupy 22.4 L at STP.
1 mole of CO occupied 22.4 L at STP.
Therefore, Xmol of CO will occupy 4.3 L at STP i.e
Xmol of CO = 4.3 / 22.4
Xmol of CO = 0.192 mole.
Thus, 0.192 mole of CO occupy 4.3 L at STP.
Finally, we shall determine the mass of CO as follow:
Mole of CO = 0.192 mole.
Molar mass of CO = 12 + 16 = 28 g/mol
Mass of CO =?
Mole = mass /Molar mass
0.192 = mass of CO / 28
Cross multiply
Mass of CO = 0.192 × 28
Mass of CO = 5.38 g.
Therefore, 5.38 g of CO occupied 4.3 L at STP.
A student walks 15 km in 3 hours. What is the student’s average speed?
A :45 km/h
B :5 km/h
12 : km/h
18 : km/h
Answer:
5 km/h
Explanation:
divide the hours to the distance
if you start with 362 grams of C3 H8 how many grams of H2O will be produced
Answer:
52 g H2O (to 2 significant figures)
Explanation:
I hope you like my answer:)
Can you mark me as brainliest please
Perform the following
mathematical operation, and
report the answer to the
appropriate number of
significant figures.
15.673 + 14.752 + 8.4568 = [?]
Answer:
38.882
Explanation:
For all those Acellus kids XD
The pH scale for acids and bases ranges from
A. 17
B. 0-14
C. 1-14
D. 1-12
Answer: 0-14
Explanation: Hope this helps
How does wood produce chemical energy?
Wood absorbs oxygen to produce chemical energy.
Wood absorbs solar radiation to make chemical energy
Wood absorbs nitrogen gas to make chemical energy.
All living organisms produce unlimited amount of chemical energy.
Answer:
Wood absorbs solar radiation to make chemical energy.
The chemical energy of wood has been absorbed by solar radiation. Thus, option B is correct.
The wood has been the source of energy by the burning for a long duration. The chemical energy has been stored in the dry wood has been converted to light and heat energy on burning.
The energy stored in the wood has been comprised by photosynthesis, where the solar energy has been entrapped in the wood and is converted to chemical energy that is stored.
Thus, the chemical energy of wood has been absorbed by solar radiation. Thus, option B is correct.
For more information about the stored energy of wood, refer to the link:
https://brainly.com/question/20326508
Silver nitride is formed when a silver cation that has a 1+ charge combines with a nitrogen anion that has a 3- charge. Write the formula for the compound silver nitride.
When hydrogen reacts with calcium metal, what are the oxidation numbers of the calcium and hydrogen in the CaH2 product?
Ca(s)+ H2(g) → CaH2
a. +2 and -1
b. +1 and -2
c. +2 and 2
d. 0 and 0
e. -2 and +1
Answer: e. -2 and +1
Explanation:
Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.
Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation number of the substance increases.
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation number of the substance gets reduced.
[tex]Ca(s)+H_2(g)\rightarrow CaH_2[/tex]
The oxidation number of calcium (Ca) in free state is 0 and in [tex]CaH_2[/tex] , it is -2.
The oxidation number of hydrogen in [tex]H_2[/tex] is zero and oxidation number of hydrogen in [tex]CaH_2[/tex] is +1 as in hydrides hydrogen loses electrons.
The oxidation number of calcium has been +2, and the oxidation number of hydrogen has been -1. Thus, the correct option is A.
The oxidation number can be defined as the number of electrons that have been lost by an atom in a chemical reaction.
The oxidation number can be calculated as the:
The oxidation number of Hydrogen when it combines with the less electronegative element has been -1.
There have been 2 atoms of Hydrogen that lose an electron, thus the total oxidation contribution of hydrogen has been -2.
The oxidation number of hydrogen has been -1.
The oxidation number of Calcium has been:
Ca atom has taken an electron from the hydrogen.
[tex]\rm Ca\;+\;e^-\;\rightarrow\;Ca^-[/tex]
The calcium takes one electron from each atom bonded. Thus the oxidation number of calcium has been +2.
The oxidation number of calcium has been +2, and the oxidation number of hydrogen has been -1. Thus, the correct option is A.
For more information about oxidation numbers, refer to the link:
https://brainly.com/question/15167411
What is the mass of 0.20 moles of Ga₂(SO₃)₃?
Answer:
75.924 g
Explanation:
To answer this question we first need to calculate the molar mass of Ga₂(SO₃)₃:
Molar Mass of Ga₂(SO₃)₃ = (Molar Mass of Ga)*2 + (Molar Mass of SO₃)*3
Molar Mass of SO₃ = Molar Mass of S + (Molar Mass of O)*3 = 80.06 g/molMolar Mass of Ga₂(SO₃)₃ = (69.72 g/mol)*2 + (80.06 g/mol) * 3
Molar Mass of Ga₂(SO₃)₃ = 379.62 g/molThen we convert 0.20 moles to grams, using the molar mass of Ga₂(SO₃)₃:
0.20 mol Ga₂(SO₃)₃ * 379.62 g/mol = 75.924 gMass of 0.20 moles of Ga₂(SO₃)₃ is 75.924 g
Number of moles:It is defined as the ratio of given mass over molar mass.
Given:
Number of moles= 0.20 moles
To find:
Mass=?
We need to calculate molar mass of Ga₂(SO₃)₃ first:
Molar Mass of Ga₂(SO₃)₃ = (Molar Mass of Ga)*2 + (Molar Mass of SO₃)*3
Molar Mass of SO₃ = Molar Mass of S + (Molar Mass of O)*3 = 80.06 g/mol
Molar Mass of Ga_2(SO_3)_3 = (69.72 g/mol)*2 + (80.06 g/mol) * 3
Molar Mass of Ga₂(SO₃)₃ = 379.62 g/mol
Then we convert 0.20 moles to grams, using the molar mass of Ga₂(SO₃)₃:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} \\\\\text{Given mass}=\text{Number of moles}*\text{Molar mass}\\\\\text{Given mass}=0.20 moles*379.62 g/mol\\\\\text{Given mass}=75.92 grams\\[/tex]
Thus, the mass of 0.20 moles of Ga₂(SO₃)₃ is 75.92 grams.
Learn more:
brainly.com/question/14464650
Please answer!!! Will give brainliest to best answer!!
1. What is the difference between magma and lava?
2. Under what circumstances do large crystals form from a cooling magma?
3. Under what circumstances do small crystals form from a cooling magma?
4. What happens to the mineral particles in salt water when the water evaporates?
5. Explain how halite forms.
6. Explain how mineral veins form.
Answer:
I can answer 1, lqva is magma outside of the volcano
24. H.SO, has
a) Ionic bond
b) both lonic and covalent bonds
c) ionic covalent and coordinate bonds
d) covalent bond
Answer:
b
Explanation:
Both ionic and covalent bonds when it has dissolved into water it will become ionic compound but when it was in gas situation it was covalent compound.
_______ are white blood cells that recognize specific antigens, and ultimately destroy them.
O lymphocytes
O pathogens
O water
Answer:
Lymphocytes
Explanation:
Pathogens are particles that make you sick like bacteria, viruses, amoebas. Water is essential for life but that's for metabolism, not fighting off against infection or viruses.
Answer:
Lymphocytes
Explanation:
lymphocytes are a kind of white blood cell (WBC). Lymphocytes are cells of the immune system and help fight infection. Lymphocytes live in lymph nodes, but also in the bloodstream and all over the body. Lymphocytes come in two main types: B-cells and T-cells
Where as water is totally not white blood cells and pathogens are viruses and bacterium