Answer:
B, liquid to solid.
Explanation: Since heat is being released, the particles for H2O would clump up. Heat is basically being taken out.
A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy without itself being consumed by the reaction.
Answer: Precision means that measurements are close to each other . Accuracy means that measurements are close to accepted value
Explanation:
Precision refers to the closeness of two or more measurements to each other.
For Example: If we weigh a given substance five times and you get 5.0 kg each time. Then the measurement is very precise.
Accuracy refers to the closeness of a measured value to a standard or known value.
For Example: If the mass of a substance is 5.0 kg and one person weighed 4.9 kg and another person weighed 3.9 kg. Then, the weight measured by first person is more accurate.
Thus Precision means that measurements are close to each other . Accuracy means that measurements are close to accepted value.
Answer:
1218.585
Explanation:
Looking at the subscripts we know there are 2 atoms of Fe, 3 atoms of C, and 6 of O.
Take the molar mass of each atom (from the periodic table) and multiply by the # of atoms
Fe: 55.845×2= 111.69
C: 12.011×3= 36.033
O:15.999×6=95.994
Add the values together: 243.717 g/mol
That is 1 mole of the molecule. Multiply by 5 for the final answer.
243.717×5=1218.585
To determine the k for the second condition, we use the Arrhenius equation which relates the rates of reaction at different temperatures. We do as follows:
ln k1/k2 = E / R (1/T2 - 1/T1) where E is the activation energy and R universal gas constant.
ln 1.80x10^-2 / k2 = 80000 / 8.314 ( 1/723.15 - 1/593.15)
k2 = 0.3325 L / mol-s
