At constant pressure, which of these systems do work on the surroundings? Check all that apply.

2A (g) + B(s) --> 3C(g)
2A (g) +2B (g) -->5C(g)
A(g)+ B(g) --> C(g)
A (s) +2B(g)--> C(g)

Is this the same post with a different screen name? See above for my response to AKLE.

No this is a different person. Thanks I got it.

Glad to be of help.

To determine which systems do work on the surroundings at constant pressure, we need to identify the systems that involve a change in the volume of gas.

When a gas expands or contracts against a constant pressure, work is done on the surroundings. On the other hand, if the volume remains constant, no work is done on the surroundings.

Let's analyze each system:

1. 2A(g) + B(s) --> 3C(g)
In this system, there is a solid (B) present, which does not contribute to a change in volume. So, this system does not do work on the surroundings.

2. 2A(g) + 2B(g) --> 5C(g)
Here, we have multiple gaseous reactants (A and B) and gaseous products (C). The change in the number of moles of gas indicates a change in volume. Therefore, this system does work on the surroundings.

3. A(g) + B(g) --> C(g)
This system involves gaseous reactants and a gaseous product. Similar to the previous system, there is a change in the number of moles of gas, indicating a change in volume. Thus, this system does work on the surroundings.

4. A(s) + 2B(g) --> C(g)
In this system, there is a solid reactant (A) that does not change in volume. However, the gaseous reactant (B) does contribute to a change in volume. Therefore, this system does work on the surroundings.

So, the systems that do work on the surroundings at constant pressure are:

- 2A(g) + 2B(g) --> 5C(g)
- A(g) + B(g) --> C(g)
- A(s) + 2B(g) --> C(g)