name the two criteria that is used to determine if a substance is pure or not
Answer:
Melting and Boiling Point Determination
The physical properties of a substance can be used to establish its purity. These properties include the melting point and boiling point. Different substances tend to have different melting and boiling points, and any pure substance will have a specific melting and boiling point.
#3. How does a fever aid an immune response?
Answer:
it can tell and show what pathogen is in you as well what type and mutation so then your body can fight back and remember the genetic dna so then you will be immune in some way.
Explanation:
Question;
How does a fever aid an immune response?
Answer:
One type of immune cell jumps into the fray after body temperature rises, according to experiments in mice. A fever fights infection by helping immune cells to crawl along blood-vessel walls to attack invading microbes
Determine the molecular formula for a compound that has a molecular mass of 52.0 g/mole
and and is composed of 92.31% carbon and 7.69% hydrogen.
Answer:
C4H4
Explanation:
92.31% of 52.0 g/mol is 48.0012 g/mol
7.69% of 52.0 g/mol is is 3.9988 g/mol
Carbon has a gram-formula mass of about 12, which goes into 48.0012 about 4 times, so there should be 4 atoms of Carbon
Hydrogen has a gram-formula mass of about 1, which goes into 3.9988 about 4 times, so there should also be 4 atoms of hydrogen
1. Mixing Water at Two Temperatures
a. One flask contains 150.0 g water at 20.0 °C. A second flask contains 350.0 g water at 95.0 °C. If the two water samples are mixed, what will the final temperature of the water be?
-Assume that the density of water it 1.000 g/cm^3
-The specific heat capacity for water is 4.184 J/g °C
Answer:
[tex]T_f=72.5\°C[/tex]
Explanation:
Hello!
In this case, since this a problem in which the cold water is heated by the hot water, we can write:
[tex]Q_{hot}+Q_{cold}=0[/tex]
Thus, by plugging in the mass, specific heat and temperatures, we obtain:
[tex]m_{hot}C_{hot}(T_f-T_{hot})+m_{cold}C_{cold}(T_f-T_{cold})=0[/tex]
Now, we can also write:
[tex]m_{hot}(T_f-T_{hot})+m_{cold}(T_f-T_{cold})=0[/tex]
Then, after applying some algebra, it is possible to obtain:
[tex]T_f=\frac{m_{hot}T_{hot}+m_{cold}T_{cold}}{m_{hot}+m_{cold}}[/tex]
If we plug in, we obtain:
[tex]T_f=\frac{350.0g*95.0\°C+150.0g*20.0\°C}{350.0g+150.0g}[/tex]
[tex]T_f=72.5\°C[/tex]
Best regards!
pls help me on this it's about acceleration
Answer:
1: A b/c the table is showing that each different surface resulted in different time for acceleration.
2: D b/c the if the same force is applied to two different masses, the smaller masses would be impacted more and move faster. The larger an object is, then the greater the force you will need for it to move the same distance as the smaller masses.
Please help :) hope you have a good day
Have a wonderful day :) thanks for the points
neptune has an average distance to the sun of 30.06 au in two or more complete sentences explain how to calculate the orbital period of neptune
Answer:
As per Kepler's law we know that \frac{T_1^2}{T_2^2} = \frac{R_1^3}{R_2^3}T22T12=R23R13as we know that for earth the time period is 1 year and its distance is 1 AUnow from above formula we can saylet the time period of Neptune is T and its distance is given as R = 30.06 AUnow we will have\frac{1^2}{T^2} = \frac{1^3}{30.06^3}T212=30.06313by rearranging the above equation we haveT^2 = (30.06)^3T2=(30.06)3T = 164.8 yearsT=164.8yearsso it will have time period of 164.8 yearsThe compound cobalt (II) sulfate forms a hydrate with seven water molecules per formula unit. What are the name and formula of the hydrate
Answer: The formula of the hydrate will be [tex]CuSO_4.7H_2O[/tex] and the name of the compound is copper sulphate heptahydrate.
Explanation:
Water of crystallisation is the number of water molecules that combine chemically in definite molecular proportion with the concerned salt in the crystalline state.
The formula of the hydrate will be [tex]CuSO_4.7H_2O[/tex] and the name of the compound is copper (II) sulphate heptahydrate as there are 7 molecules of water.
Zn(s) + 2 HCl(aq) —> ZnCl2(aq)
+ H2(g)
If a scientist wanted to create 10L of hydrogen gas at RTP, what mass of HCl would they need to start with?
Answer:
First write the balanced equation for the reaction of HCl with Zn (NOTE: the previous answer did NOT do this and thus obtained an incorrect answer)
Zn + 2HCl ==> ZnCl2 + H2(g)
moles of H2 desired: PV = nRT
n = PV/RT = (1 atm)(10L)/(0.0821 Latm/Kmol)(298K)
n = 0.409 mole H2 desired
moles Zn needed:
0.409 moles H2 x 1 mole Zn/2 moles HCl = 0.204 moles Zn needed
mass Zn needed = 0.204 moles Zn x 65.4 g/mol = 13.4 g Zn needed (to 3 sig. figs.)
Explanation:people always get this wrong but i got you
3.Which of these is NOT part of the cell theory? * "
all living things are made of cells
Ocells come only from other cells
cells are the smallest living unit of an organism
O all living things have blood cells
Answer:
Cells are the smallest living unit of an organism
Answer:
all living things living things have blood cells
Explanation:
this is because robert hooke did not make this apart of the theory
How many particles are in 4g of NaCl? (1mol of NaCl = 58g) – 2 step conversion
Answer:
4.16 * 10²⁴ particles
Explanation:
1. We convert from grams to moles
4 g NaCl / 58 g of NaCl = 0.0689655172 moles
-> 0.0690 moles
2. Now we will convert from moles to particles by multiplying by avogadro's number..
0.0690 * 6.022 *10²³ = 4.15518 * 10²⁴ particles or 4.16 * 10²⁴ particles