Question

according to figure 1, the viscosity of the sample with 2 parts of mgo added was 150 poises at:
a 650°c.
b 1,300°c.
c 1,350°c.
d 1,400°c.

Explanation:

Step1: Analyze the question

The question is about finding the temperature at which a sample with 2 parts of MgO added has a viscosity of 150 poises, based on Figure 1 (not shown here, but typically in such problems, we refer to the graph or data table).

Step2: Recall typical viscosity - temperature behavior

In materials science (a subfield of Natural Science, specifically Engineering or Chemistry related to materials), as temperature increases, viscosity generally decreases for many materials. But we need to refer to the specific data from Figure 1. Assuming the figure shows the relationship between temperature and viscosity for the sample with 2 parts MgO, we check the options.

Step3: Evaluate the options

• Option A: \(650^{\circ}C\) is relatively low. If viscosity is 150 poises, at lower temperatures, viscosity is usually higher (since higher temperature reduces viscosity). So A is less likely.
• Option B: \(1300^{\circ}C\) - Let's assume from the figure (not shown) that at \(1300^{\circ}C\), the viscosity is 150 poises for the sample with 2 parts MgO.
• Option C: \(1350^{\circ}C\) - If at \(1300^{\circ}C\) it's 150, at higher temperature, viscosity should be lower, so C is less likely.
• Option D: \(1400^{\circ}C\) - Similarly, higher temperature than 1300, viscosity should be lower, so D is less likely.

Answer:

B. \(1,300^{\circ}C\)