The variable that is observed during an experiment is called what type of variable?

What is the five part definition for an object to be considered a mineral

2C2H2 + 5 O2 → 4CO2 + 2H2O Use the given standard enthalpies of formation to calculate ∆H for this reaction C2H2 = 227.4 CO2 = - 393.5 H2O = - 241.8 1256.2 kJ b. - 1256.2 kJ c. - 2512.4 kJ d. 2512.4 kJ

a solution of household vinegar is to be analyzed. A pipet is used to measure out 10 ml of the vinegar which is placed in a 250ml volumetric flask.

Find the pH of the 0.169 M NaOH solution in problem 4 (assume that the NaOH dissociates completely into Na and OH-) and its associated absolute uncertainty by propagating the uncertainty in concentration found in part b of the problem.

Which of the following cell structures exhibits selective permeability between a cell and its external environment?

In the synthesis reaction, the white powder produced is magnesium oxide (mgo, mm = 40.3 g/mol). how many moles of magnesium oxide were formed (number of moles = mass (g) / molar mass (g/mol)) ? choose the closest answer. a. 0.21 moles b. 0.

Which of the following is the most likeley example of an favorable mutation A. A mutation that makes a rabbit able run faster B. A mutation that changes the rabbit's fur to bright orange C. A mutation that changes the color of the rabbit's eyes D.

Which of these mole ratios is possible for this reaction? FeCl3 + 3NaOH → Fe (OH) 3 + 3NaCl 1:1 1:3 3:1 2:3

The chemical equation for reduction of phosphorite Ca3 (PO4) 2

Synthesize What environmental effects are shared by all fossil fuels?