Answer:
a solution color becoming less intense due to dilution- is not an evidence of a chemical reaction
bubbles (gas formation) - evidence of a chemical reaction
explosion or fire - evidence of a chemical reaction
changes in color- evidence of a chemical reaction
precipitation- evidence of a chemical reaction
changes in temperature - evidence of a chemical reaction
a solid liquifying - is not an evidence of a chemical reaction
solution colors mixing - is not an evidence of a chemical reaction
Explanation:
A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.
In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.
For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.
Answer:
1. 176 × 10^12 W ; 78400000000
Explanation:
Given the following :
Fall rate = 2,400,000kg/s
Average height of fall = 50m
Gravitational Potential of falling water = mgh = mass × acceleration due to gravity × height =
How many 15 W LED light bulbs could it power?
Recall : power = workdone / time
Workdone = gravitational potential energy
Mass of water = density * volume
Density of water = 1 * 10^3kg/m^3
Rate of fow = volume / time = 2400000
Hence,
Power = 1000 * 2,400,000 * 9.8 * 50
Power = 1176000000000
Power = 1. 176 × 10^12 W
How many 15 W LED light bulbs could it power?
1176000000000 / 15 = 78400000000
= 78400000000 15 W bulbs
Answer:
Mass = 179.9 g
Explanation:
Given data:
Volume of solution = 450 mL
Molarity of solution = 2.00 M
Mass in gram required = ?
Solution:
Volume of solution = 450 mL× 1 L / 1000 mL = 0.45 L
Molarity = number of moles of solute/ Volume of solution in L
2.00 M = number of moles of solute / 0.45 L
Number of moles of solute = 2.00 M × 0.45 L
M = mol/L
number of moles of solute = 0.9 mol
Mass of CaBr₂ in gram:
Mass = number of moles × molar mass
Mass = 0.9 mol ×199.89 g/mol
Mass = 179.9 g
A vapor is which state of matter?
C. Gas.
