Answer:
B. Independent variable
Explanation:
In an experiment, the independent variable is the variable that the experimenter manipulates or changes in order to effect a response in another variable, called the dependent variable.
In this experiment where Rachel adds varying amount of light in order to see how it impacts plant growth over time. The independent variable is the SUNLIGHT because it is what is changed or manipulated by Rachel. The dependent variable is the plant growth.
The equation is:
3 O₂ + 4 Co → 2 Co₂O₃
Oxidation half reaction:
Co → Co³⁺ + 3 e
Reduction half reaction:
O₂ + 4 e → 2 O²⁻
To balance the equation number of electrons lost must be equal to number or electrons gained so we must multiply oxidation half time 4 and reduction half times 3
Answer is: C. Reactants combine to form products.
In a chemical reaction, chemical bonds are forming and breaking and this cause the transformation of one group of chemical substances to another
For example synthesis of water from its elements: 2H₂ + O₂ → 2H₂O, nonpolar bonds between hydrogen and oxygen atoms (reactants) are breaking and new polar bonds are forming between hydrogen and oxygen in molecule of water (product).
Answer:
The molecular weight for the compound is 60.1 g/mol
Explanation:
We need to determine the molality of solute to find out the molar mass of it.
We apply the colligative property of freezing point depression:
ΔT = Kf . m . i
If the compound was also found to be nonvolatile and a non-electrolyte,
i = 1.
Freezing T° of pure solvent - Freezing T° of solution = Kf . m
0°C - (-2.05°C) = 1.86°C/m . m
2.05°C / 1.86m/°C = m → 1.10 mol/kg
To determine the moles of solute we used, we can multiply molality by the mass of solvent in kg → 202.1 g . 1kg/1000g = 0.2021 kg
1.10 mol/kg . 0.2021kg = 0.223 moles
Molar mass→ g/mol → 13.39 g / 0.223 mol = 60.1 g/mol