Answer:
-4.1°C
Explanation:
The freezing-point depression (ΔTf) is a colligative property that can be calculated using the following expression:
ΔTf = i × Kf × m
where,
i: van't Hoff factor
Kf: freezing-point depression constant
m: molality
ΔTf = 1.9 × 1.86°C/m × 1.15 m = 4.1 °C
The freezing-point of pure water is 0°C. The freezing-point of this solution is:
0°C - 4.1°C = -4.1°C
Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the actual or formal transfer of electrons between chemical species, most often with one species undergoing oxidation while another species undergoes reduction.
Answer:
The substance which responds to the change in the concentration of the hydronium ions in solution by changing its color is known as an indicator.
the cut pieces will have their own north and south pole
People firstly believe that the planets move in a circular orbit until Newton came up with his hypothesis by inventing calculus so that we could understood and calculated planetary orbits and their accuracy.
<u>Explanation:</u>
- Everyone assumed the planets were perfect circles until Newton came up with an idea. Slowly people would make maps of the orbits that added circles on circles, and they could never really explain about the movement of the planet. They simply say that planets move on circles but they lacked the math to explain or prove it. Then Newton came up with an idea of inventing calculus so that we could understood and calculated planetary orbits and their accuracy.
- Firstly people used their observations and say that the orbits looked like circles, then they developed their models and did the math, and proposed their hypothesizes which were wrong, until Newton came along and tried to match a model that used elliptical orbits and invented the math that allowed him to make predictions with it. His model worked for most planets.
- However he could not explain about the planet Mercury for instance since it was a very strange orbit. Then after the Einstein's theory of General Relativity he could also explain very deeply about it.
- Scientists and Astronomers made hypothesizes that there was another planet orbiting too close to the sun to see with telescopes, called Vulcan, that explained mercury's orbit before Einstein's theory. Then long after we had telescopes which was good enough to see if there was a planet orbiting closer to the sun than mercury.
