what is the dewpoint temperature of a kilogram of air when a psychrometer measures an 8 degree Celsius dry-bulb temperature and a 6 degree Celsius wet-bulb reading?

The amount (weight) of the air has nothing to do with it. Either dew forms or it doesn't. You need a psychrometric chart to answer the question. There are numerous online sites to help you with a chart or a computational tool.

Using http://www.csgnetwork.com/dewptrelhumcalc.html
and using Fahrenheit temperatures for the wet and dry bulb temps (which is unfortunately required at that site) , I get 3.77 C for the dew point.

To calculate the dew point temperature using the psychrometric chart, we need to follow these steps:

Step 1: Find the dry-bulb temperature on the x-axis of the chart. In this case, the dry-bulb temperature is 8 degrees Celsius.

Step 2: Find the wet-bulb depression, which is the difference between the dry-bulb temperature and the wet-bulb temperature. In this case, it is 8 - 6 = 2 degrees Celsius.

Step 3: Draw a horizontal line from the point on the x-axis corresponding to the dry-bulb temperature (8 degrees Celsius).

Step 4: From the point where the line intersects the chart curve, draw a vertical line downward until it reaches the line representing the wet-bulb depression (2 degrees Celsius).

Step 5: From the intersection point, draw a horizontal line to the left until it reaches the y-axis. This will give you the dew point temperature.

According to the psychrometric chart, when the dry-bulb temperature is 8 degrees Celsius and the wet-bulb temperature is 6 degrees Celsius, the approximate dew point temperature is around 4 degrees Celsius.

To find the dewpoint temperature, we need to use the dry-bulb and wet-bulb temperature readings provided by the psychrometer. The dewpoint temperature is the temperature at which the air becomes saturated and condensation begins to form.

First, we need to calculate the difference between the dry-bulb and wet-bulb temperatures. In this case, the difference is 8°C - 6°C = 2°C.

Next, we need to use a table or a chart known as a psychrometric chart. This chart relates the dry-bulb temperature, wet-bulb temperature, and dewpoint temperature. It provides a quick way to determine the dewpoint temperature based on these readings.

Referencing the psychrometric chart, find the intersection point of the dry-bulb temperature of 8°C and the wet-bulb temperature of 6°C. Draw a straight line from this point to the right until it intersects with the dashed curved line labeled "Saturation Mixing Ratio."

From this intersection point, draw a straight line vertically downward until it intersects with the bottom scale labeled "Dewpoint Temperature." This point will give you the dewpoint temperature corresponding to the given dry-bulb and wet-bulb temperatures.

The dewpoint temperature for a kilogram of air with a dry-bulb temperature of 8°C and a wet-bulb temperature of 6°C would be approximately 4.5°C, based on the chart.

Please note that the accuracy of the result may vary depending on the specific psychrometric chart and its scale. For precise calculations, you may need to use equations or online tools that utilize more detailed thermodynamic properties of air.