Temperature (°C) 5
Heating Curve for Water
160
140
2 120
100
80
60
40
20
0
-20
1 2 3 4 5 6 7
Time (min)
8
9
10
At what temperature does the solid start melting?
0 -20°C
0°C
20°C
80°C
Answers
Answer:
Showing results for Temperature (°C) 5 Heating Curve for Water 160 140 2 120 100 80 60 40 20 0 "-20" 1 2 3 4 5 6 7 Time (min) 8 9 10 At what temperature does the solid start melting?
Related Questions
The seedlings that we planted on the newspaper cuttings or cotton wool did not grow very well at all, even though they had sunlight and water. What could they not get from the newspaper or cotton wool that plants normally get from soil?
Answers
Give reasons. a. Troposphere is affected maximum by human activities.
Answers
Answer:
it is where the ozone layer is locate which is affected by human activities
19. If 23.4 grams of hydrogen gas were produced by the reaction below, how many grams of aluminum chloride were produced? (2 points) 2 Al + 6 HCl yields 2 AlCl3 + 3 H2 516 g AlCl3 774 g AlCl3 1030 g AlCl3 1550 g AlCl3
Answers
Answer:
1040
Explanation:
you can use the mole to mole ratios of aluminum chloride and hydrogen gas,you first have to find the number of moles of hydrogen gas..the number of moles of hydrogen gas are 11.7(23.4/2)
2AlCl3+3H2
2 : 3
x :11.7
3x/3=23.4/3
x=7.8g/mol
then find the number of grams of aluminum chloride
m=n×mr
=7.8×133.341
=1040g
I hope this helps and sorry if it's wrong
How many grams of solute is there in 250 mL of a 0.10M CaCl2 solution ?
Answers
Answer:
2.775 g
Explanation:
Given that;
Number of moles = concentration × volume
Concentration = 0.10M
Volume =250 mL
Number of moles = 250/1000 × 0.10
Number of moles = 0.025 moles
Also;
Number of moles = mass/molar mass
Molar mass of CaCl2= 111 g/mol
Mass = Number of moles × molar mass
Mass = 0.025 moles × 111 g/mol
Mass= 2.775 g
from the equation 2PbO + C = 2Pb + CO2, detemine which one is reactant is oxidised and which is reduced.
Answers
Answer:
Explanation:
C is oxidised because C up to C+4
PbO is reduced because PbO from Pb2+ down to Pb0
Answer:
lead (Pb) is reduced carbon is oxidized
hii pls help me to balance the equation and state the symbols thanksss
Answers
Ca(s)+ H2O (l)----->H2 +Ca(oH)2
Ca(s)+2H2O(l)----->H2(g)+Ca(oH)2
I hope this helps
sorry if it's wrong
Which of the following would not be considered matter?
clouds
trees
rain
air
light
Answers
Answer:
light
Explanation:
Have a nice day
Answer:
light
Explanation:
The presence of which gas makes the planets Uranus and Neptune appear blue?
a. helium
b. hydrogen
c. methane
d. nitrogen
Answers
Answer:
C. METHANE
Explanation:
The blue color of both the ice giants can be contributed to the presence of methane in their upper atmospheres. Methane absorbs most of the red light incident on the planets which makes them appear blue in color.
that B) My color is sickle: I have a drop of water in my body when I was given heat, white powder was formed So who am i Lets identify. Write my chemical molecular formula
Answers
Explanation:
i don't understood your question ⁉️
and what do u mean by my color is sickle
why is the Dna molecule able to open up and close?
Answers
Answer:
The breaking of the hydrogen bonds due to the force relieves the torsional stress stored in a double helix. As a result, the nucleotide strands rotate more freely about the axis of a helix and start unwinding. ... The DNA unzipping and the DNA unwinding result in a structural transformation from dsDNA to ssDNA.
If 16.4 grams of calcium nitrate is heated as shown in the reaction:
2Ca(NO3)2 -> 2CaO + 4NO2 + O2.
Calculate the volume of nitrogen dioxide produced at STP.
Answers
Answer:
7.2
Explanation:
you first have to find the number of moles of nitrogen dioxide by using the number of moles for calcium nitrate and the mole to mole ratios
number of moles of calcium nitrate=mass/mm
=16.4/102
=0.16g/mol
then you use the mole to mole ratios
2 : 4
0.16: x
2x/2=0.64/2
x=0.32g/moles of nitrogen dioxide
then you use the formula for the volume
v=22.4n
=22.4×0.32
=7.2
I hope this helps
Which fossil fuel is the remains of ancient plants?
A. Coal
B. Petroleum
C. Natural Gas
Answers
A. Coal
Others are animal remains
The fossil fuel which is the remains of ancient plants is: A. Coal.
Non-renewable energy can be defined as a type of energy that is mainly generated through artificial sources or from the remains of ancient plants.
Hence, a non-renewable energy cannot be replenished or renewed like the renewable energy sources.
Basically, some examples of a non-renewable energy include:
Natural gas.Petroleum.Coal.Other fossil fuels.Coal deposits are typically petrified peat swamps and peat is generated from decaying plants.
Also, coal has been discovered to be a fossil fuel that contain the remains of ancient plants, based on radioactive dating.
Read more: https://brainly.com/question/22527860
PLZ HELP Matthew wants to study how the body responds when the skin is broken. He learns that particles in the blood clump together at the site of the wound to stop the bleeding while the skin heals. Which of the following body systems is involved in carrying the blood to the site of the wound?
A. Cardiovascular
B. Skeletal
C. Respiratory
D. Muscular
Answers
Answer:
A, Cardiovascular system
cardiovascular system
state the modern periodic law
Answers
Answer:
The modern periodic law states that the physical and chemical properties of the elements are the periodic function of the atomic numbers and electronic configurations. ... This repetition occurs if the arrangement of the elements is in order of their increasing atomic numbers.
In a synthesis experiment you obtain a sample of product on which you do a melting point determination and find a melting point range of 114 to 125 degrees Celsius. The sample is supposed to be acetylsalicyclic acid. What preliminary conclusion(s) can you reach from this one determination
Answers
Answer:
The melting point determination may need improvement- it may not have been done properly, and make sure it was repeated at least once.
Explanation:
Given that we know the actual melting point of pure acetylsalicyclic acid to be 135°, it follows that the process followed to obtain the melting point range of 114 to 125 degrees Celsius must be inaccurate.
Therefore, we can conclude that, the melting point determination may need improvement. It may not have been done properly, and we must make sure it is repeated at least once.
C4H9OH have several isomers. Draw structure and IUPAC names of its three isomers.
Answers
Answer:
.
Explanation:
Salt is often used to melt ice on roads during the winter because it lowers the freezing/melting point of water. When salt dissolves in water, individual Na and Cl- ions break away from the salt lattice and become surrounded by water molecules. Why would this cause ice to melt
Answers
Answer:
See explanation
Explanation:
The addition of an impurity lowers the melting point of a solid. If we add salt to ice, the melting point of the ice is lowered.
As this salty water is in contact with the ice, more of the salt dissolves to yield Na^+ and Cl^- and leads to the melting of more ice.
Freezing point is a colligative property hence it is affected by the presence of impurities. Hence, the addition of NaCl causes ice to melt faster.
A(n) _____ is a hydrocarbon in which one or more hydrogen atoms is replaced by a -COOH and a -NH2 group. aldehyde carboxylic acid alcohol amino acid
Answers
Answer:
Amino Acid
Explanation:
It's part of the Amino group, which are substituted hydrocarbons.
When NH₂ and COOH replaces hydrogens on the same carbon atom in a molecule, an Amino acid is formed.
What group is a COOH?
COOH : a Carboxylic Acid group!
which of the following statements is true about alkali?
A) bases that soluble in water
B) shows a pH value less than 7
C) Ionises in water to form hydroxonium ions
D) Reacts with carbonate salt to release carbon dioxide gas
Answers
Answer:
it should be letter c
Explanation:
I hope this help
Which of the following elements would you expect to be most reactive, based
on the number of valence electrons it has?
Answers
Answer:
C. Lithium
Explanation:
This image describes the trend in reactivity. Group 1 metals are always the most reactive so yeah :)
Which statement describes a condensation reaction?
A. monomers break away when one forms a double bond monomers break away with the addition of a water molecule.
B. Two monomers combine when one adds to the double bond of another.
C. Two monomers form a new bond with the loss of a water molecule .
Answers
The statement that describes a CONDENSATION reaction is that two monomers form a new bond with the loss of a water molecule . That is option C.
CONDENSATION REACTION involves the combination of two or more molecules(monomers) of water. In reaction, a new bond is usually formed.
The characteristics of a condensation reaction includes:
formation of complex molecules (combination of two smaller monomers),water is usually given off as by product it requires a catalyst for a complete reaction to occurA reaction is called a condensation reaction because a small molecule such as water is released as a byproduct.
A typical example of a condensation reaction is the condensation of amino acids to form dipeptide. The −OH from the carboxyl group of one amino acid combines with a hydrogen atom from the amine group of the other amino acid to produce water.
Therefore, the statement that describes a CONDENSATION reaction is that two monomers form a new bond with the loss of a water molecule. That is option C
Learn more about condensation here:
https://brainly.com/question/16350693
what is mean by measurement
Answers
Answer:
Measurement is defined as the act of measuring or the size of something. An example of measurement means the use of a ruler to determine the length of a piece of paper. ... Extent, quality, or size as determined by measuring; dimension. A waist measurement of 32 inches.
Explanation:
The comparison o unknown quantity with known standard quantity is called measurement.
calculate the maximum mass of ethanol that could be obtained from 30.0g of glucose
Answers
Answer:
15.3g
Explanation:
C6H12O6 → 2C2H5OH + 2CO2
1 mol C6H12O6 = 180g
1 mol CH3-CH2-OH = 46g
From 180g glucose ethanol can get = 92g
30g glucose ethanol gives us = (92*30)/180 = 15.33g
True or false, the four units that must always be used when using the ideal gas law are liters, atm, Kelvin, and grams
Answers
Answer:
False grams is not used
Explanation:
IDEAL GAS LAW
The ideal gas law states that PV = NkT, where P is the absolute pressure of a gas, V is the volume it occupies, N is the number of atoms and molecules in the gas, and T is its absolute temperature.
It is necessary to use Kelvin for the temperature and it is conventional to use the SI unit of liters for the volume. However, pressure is commonly measured in one of three units: kPa , atm , or mmHg . Therefore, R can have three different values.
What is the name of this molecule?
H3C - C ≡ C - CH3
Answer: 1,2,3, or 4-butyne?
Answers
Explanation:
The given molecule is
H3C - C ≡ C - CH3
The numbering order is shown below:
H3C - C ≡ C - CH3
1 2 3 4
So, the alkyne group is in the second position.
The carbon chain has four carbons.
Hence, the IUPAC name of the given compound is:
2-butyne.
calculate the mass of magnesium needed to make 25g of magnesium oxide
Answers
Explanation:
here's the answer to your question about
A solution, such as pure water, with a pH of 7 contains which of the following?
a. Dissolved CO2
b. Equal amounts of hydrogen ions and hydroxide ions
c. Smokestack pollutants such as sulfur dioxide
d. Sodium hydroxide
Answers
Answer:
B
Explanation:
Pure water always has equal concentrations of hydrogen and hydroxide ions.
A phase change from a solid to a gas is called:
Answers
Answer:
sublimation
Explanation:
PLZ HELP ME WITH MY WORK
For his science fair project, Martin studied the growth of trumpet vines. He grew 20 trumpet vines. All of the conditions were the same, except that he grew 10 in a flower bed without support and 10 in a flower bed near a trellis. The stems of the vines near the trellis twisted around the trellis, and these Yines grew tall and seemed much healthier than the vines grown without a trellis. In fact, four of the vines grown without a trellis died. Which characteristic of living things were the trumpet vines displaying as the stems twisted around the trellis?
A. Movement
B. Response to a stimulus
C. Use of energy
D. Reproduction
Answers
Answer:
it's B
Explanation:
Climbing plants require an external support to grow vertically and enhance light acquisition. Vines that find a suitable support have greater performance and fitness than those that remain prostrate. Therefore, the location of a suitable support is a key process in the life history of climbing plants
A sample of lithium sulfate, (Li2SO4), has 2.94 x 1023 atoms
of lithium. How many moles of lithium sulfate is the sample?
Answers
Answer:
0.245 moles
Explanation:
moles of lithium = 2*moles of Li2SO4
so moles of LI2SO4=2.94*10^23/(2*6*10^23)=0.245
One mole of lithium sulphate contains 1.2 .022 × 10²⁴ atoms. Thus, the number of moles of this compound which contains 2.94 × 10²³ Li atoms is 4.08 moles.
What is one mole?Any substance containing 6 .022 × 10²³ number of atoms is called one mole of that substance. This number is called Avogadro number. Hence, one mole of every elements or molecules contains Avogadro number of atoms.
Similarly, one mole of any compound contains 6 .022 × 10²³ molecules. The weight of one mole of a compound is called its molar mass. The mass of one mole of an element is called its atomic mass.
Hence, one mole of lithium sulphate contains 2 × 6 .022 × 10²³ atoms of lithium. Therefore, the number of moles of lithium sulphate containing 2.94 × 10²³ Li is :
Find more on Avogadro number:
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