<h3>
Answer:</h3>
298.15 K
<h3>
Explanation:</h3>
W e are supposed to calculate the Value of K at 25°C
Assuming the value of K represent K, the question wants us to convert degree Celsius to Kelvin.
- To convert degrees Celsius to kelvin scale, we use the relationship;
- Kelvin (K) = Degrees Celsius + 273.15 ; 273.5 is a constant
- That is, to convert temperature from °C to Kelvin we add a constant of 273.15 to the °C given.
In this case;
Temperature is 273.15 °c
Thus, to Kelvin scale temperature will be;
= 25°C + 273.15
= 298.15 K
Therefore, the value of K, at 25°C is 298.15 K
Melting is an example of phase change
Answer: Region 3
Explanation: The temperature and time graph suggests that region 3 is the region in which the substance can co exist in both the phases that is solid phase and liquid phase.
Region 1 explains that the the solid has just started melting and there occurs a break point and then region 2 again explains that the solid is taking more time with temperature to get converted into the liquid and thus region 3 explains the equilibrium between the two phases.
I think the answer to that is B
Answer:
1720.8g water are necessaries
Explanation:
Mass percent is defined as the mass of solute (In this case, MgCl2) in 100g of solution (Mass MgCl2 + Mass water). To solve this question we must find the mass of solution that we need to produce th 1.5% by mass solution. Thus, we can find the mass of water that we need as follows:
<em>Mass solution:</em>
26.2g MgCl2 * (100g Solution / 1.5g MgCl2) = 1747g solution
<em>Mass water:</em>
1747g solution - 26.2g MgCl2 = 1720.8g water are necessaries
