---
title: "Standard Conditions — AP Chem Definition & Exam Guide"
description: "Standard conditions in AP Chem mean 1 atm, 25°C (298 K), and 1 M solutions. That little ° symbol on ΔH°, ΔS°, ΔG°, and E° tells you these conditions apply."
canonical: "https://fiveable.me/ap-chem/key-terms/standard-conditions"
type: "key-term"
subject: "AP Chemistry"
---

# Standard Conditions — AP Chem Definition & Exam Guide

## Definition

A set reference point used by scientists which includes pressure at 1 atmosphere, temperature at 25 degrees Celsius (298K), and concentrations at 1 Molar for solutions.

## Related Study Guides

- [9.9 Cell Potential and Free Energy](/ap-chem/unit-9/cell-potential-free-energy/study-guide/GLRagoPDoMJ35XxbRbdb)
- [9.2 Absolute Entropy and Entropy Change](/ap-chem/unit-9/absolute-entropy-entropy-change/study-guide/RhcmO6DuTuEoGzcCk2zG)
- [6.8 Enthalpy of Formation](/ap-chem/unit-6/enthalpy-formation/study-guide/glO3L5mcfcUwCd0ODBej)
- [9.10 Cell Potential Under Nonstandard Conditions](/ap-chem/unit-9/cell-potential-under-non-standard-conditions/study-guide/iVpmBAtYorzFr6ljbcdT)

## Review

### Related Terms

- STP (Standard Temperature and Pressure): Specific set conditions often used in calculations involving gases; defined as zero degrees Celsius and one atmosphere pressure.
- [Molarity](/ap-chem/key-terms/molarity): A measure of concentration indicating the number of moles per liter solution.
- [Thermodynamics](/ap-chem/key-terms/thermodynamics): The study of energy changes accompanying physical and chemical transformations.