14/14 Chemical Laboratory Methods and Quantitative Analysis Free Online FlashCards

What does the RAMP framework stand for?

RAMP means Recognize hazards, Assess risks, Minimize risks, and Prepare for emergencies.

How do independent and dependent variables differ?

The independent variable is deliberately changed; the dependent variable is measured in response to that change.

What is a replicate?

A replicate repeats measurement under independently repeated experimental conditions, including relevant preparation or sampling steps.

What is the difference between precision and accuracy?

Precision is the closeness of repeated measurements to one another; accuracy is agreement with an accepted value or reference standard.

How do random and systematic errors differ?

Random error produces unpredictable trial-to-trial variation and can be reduced by replication. Systematic error shifts results consistently and is not removed by repetition alone.

What is the formula for the sample mean?

The sample mean is x̄ = (1/n) Σxᵢ, where n is the number of measurements and xᵢ is an individual measurement.

What does the standard error of the mean describe?

The standard error of the mean is sₓ̄ = s/√n. It estimates uncertainty in the mean from random sampling variation.

Which graph suits two quantitative variables?

Use a scatter plot for two quantitative variables; place the independent variable on the horizontal axis and the dependent variable on the vertical axis.

What is a residual, and what pattern supports a model?

A residual is eᵢ = yᵢ − ŷᵢ, the measured value minus the model-predicted value. Random residuals with roughly constant spread support a model.

What is the first-order law of uncertainty propagation?

For independent inputs, u²c(y) = Σ[(∂f/∂xᵢ)²u²(xᵢ)]. This combines input standard uncertainties through the measurement equation.

How are uncertainties propagated for addition or subtraction?

For addition or subtraction, combine absolute uncertainties in quadrature: u(y) = √[u(a)² + u(b)²].

How are uncertainties propagated for multiplication or division?

For multiplication or division, combine relative uncertainties in quadrature: (u(y)/y)² = (u(a)/a)² + (u(b)/b)².