In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
Answer:
Explanation:
Answer:
A. to determine the efficiency of the reaction
Explanation:
Percentage is the ratio of the actual yield to theoretical yield as a percentage. It is calculated by dividing the actual yield by theoretical yield then multiplying by 100%.
Calculation of percentage yield is important as it helps in the determination of efficiency of a reaction. For example in most industries for the purpose of making the most product with the least waste.
Additionally, calculating the percentage yield helps in determining other products that may be formed during the reactions.
1) we find out the volume of the water.
Remember: 1 ml=1 cm³
Volume of the water=number of cups x volume of one cup.
Volume of the water=2.5(240 ml)=600 ml=600 cm³
Density=mass/volume ⇒ mass=density x volume
2) we calculate the water mass of 600 cm³ of water.
mass=density x volume
mass=(1 g/cm³)(600 cm³)=600 g.
Answer: the mass of 2.5 cupas of water is 600 g.
Answer:
The answer to your question is 8.28 g of glucose
Explanation:
Data
Glucose (C₆H₁₂O₆) = ?
Ethanol (CH₃CH₂OH)
Carbon dioxide (CO₂) = 2.25 l
Pressure = 1 atm
T = 295°K
Reaction
C₆H₁₂O₆ ⇒ 2C₂H₅OH(l) +2CO₂(g)
- Calculate the number of moles
PV = nRT
Solve for n
Substitution
Simplification
n = 0.092
- Calculate the mass of glucose
1 mol of glucose --------------- 2 moles of carbon dioxide
x --------------- 0.092 moles
x = (0.092 x 1) / 2
x = 0.046 moles of glucose
Molecular weight of glucose = 180 g
180 g of glucose --------------- 1 mol
x g ---------------0.046 moles
x = (0.046 x 180) / 1
x = 8.28 g of glucose
Answer:
B
Explanation:
Assuming the units are all supposed to be the same
A cube shaped cell with a 1 um³ volume would have a dimensions of 1 x 1 x 1 (because volume = length x width x height and 1 x 1 x 1 =1)
If we double the dimensions, we have a cube with the dimensions 2 x 2 x 2.
The surface area of each face of the cube is the length x width, so 2 x 2. This means the surface area of each face of the cube is 4 um².
There are 6 faces of a cube, so the total surface area is 6 x 4 um² = 24 um².
