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3 years ago

Which phrase justifies why the theory of evolution is a theory and not a law?

Chemistry

2 answers:

Hunter-Best [27]3 years ago

7 0

Answer:

2. Makes accurate predictions based on only a small amount of empirical evidence

Explanation:

djverab [1.8K]3 years ago

5 0

Answer:

2. Makes accurate predictions based on only a small amount of empirical evidence

Explanation:

For a phrase or scientific finding to be considered a law, there has to be clear evidence and facts to support that specific finding. In the case of the evolution theory, the evidence is not clear enough to make it a law

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The part of an atom that is responsible for the bonding of atoms is

Cerrena [4.2K]

Answer:

the answer is electrons

Explanation:

electrons are responsible for the chemical bonding.

3 0

3 years ago

Consider the following balanced reaction. How many grams of water are required to form 75.9 g of HNO3? Assume that there is exce

adoni [48]

Answer:

The answer is "10.84 g".

Explanation:

The formula for calculating the number for moles:

$\text{Number of moles }= \frac{\ Mass}{ \ molar \ mass }$

In the given acid nitric:

Owing to the nitric acid mass = $75.9 g$

Nitric acid molar weight $= 63\ \frac{g}{mol}$

If they put values above the formula, they receive:

$\text{moles in nitric acid} = \frac{75.9}{63}$

$=1.204 \ mol$

In the given chemical equation:

$3 NO_2 \ (g) + H_2O \ (l) \longroghtarrow 2 HNO_3 \ (aq) + NO\ (g)$

In this reaction, 2 mols of nitric acid are produced by 1 mole of water.

So, 1.204 moles of nitric acid will be produced:

$= \frac{1}{2} \times 1.204$

$=0.602\ \ \text{mol of water}.$

We are now using Equation 1 in determining the quantity of water:

Water moles $= 0.602\ mol$

Water weight molar $= 18.02 \ \frac{g}{mol}$

$\to 0.602 = \frac{\text{mass of mols}}{ 18.02}\\\\\to \text{mass of mols} = 0.602 \times 18.02\\\\$

$=10.84 \ g$

8 0

3 years ago

Suppose that 10.0 L of Carbon Dioxide gas are produced by this reaction, 4C3H5N3O9 -> 12 CO2 + 10H2O + 6N2 +O2, at a temperat

siniylev [52]

The mass of nitroglycerin : 34.52 g

<h3>Further explanation</h3>

Reaction

4C₃H₅N₃O₉ ⇒ 12 CO₂ + 10H₂O + 6N₂ +O₂

Volume = 10 L

Temperature = -5°C=268 °K

Pressure = 1 atm

mol of CO₂ (ideal gas) :

$\tt n=\dfrac{PV}{RT}\\\\n=\dfrac{1\times 10}{0.082\times 268}\\\\n=0.455$

mol ratio C₃H₅N₃O₉ : mol CO₂= 4 : 12, so mol C₃H₅N₃O₉ :

$\tt \dfrac{4}{12}\times 0.455=0.152$

mass C₃H₅N₃O₉ (MW=227,0865 g/mol):

$\tt 0.152\times 227.0865=\boxed{\bold{34.52~g}}$

4 0

3 years ago

Flag this question question 8 10 pts use the δh°f and δh°rxn information provided to calculate δh°f for if: δh°f (kj/mol) if7(g)

GarryVolchara [31]

$\Delta H\textdegree{}_f(\text{IF} \; (g)} = -95 \; \text{kJ} \cdot \text{mol}^{-1}$

Explanation

$\text{IF}_7 \; (g) + \text{I}_2 \; (s) \to \text{IF}_5 \; (g) + 2\; \text{IF} \; (g)$

$\Delta H\textdegree{}_\text{rxn} = -89\; \text{kJ} \cdot \text{mol}^{-1}$
$\Delta H\textdegree{}_f (\text{IF}_7 \; (g) ) = -941 \; \text{kJ} \cdot \text{mol}^{-1}$ (from the question)
$\Delta H\textdegree{}_f (\text{IF}_5 \; (g) ) = -840 \; \text{kJ} \cdot \text{mol}^{-1}$ (from the question)

As an the most stable allotrope under standard conditions, $\Delta H\textdegree{}_f (\text{I}_2) = 0\; \text{kJ} \cdot \text{mol}^{-1}$

By definition,

$\Delta H\textdegree{}_\text{rxn} = \Delta H\textdegree{}_f (\text{all products}) - \Delta H\textdegree{}_f (\text{all reactants})$

$\Delta H\textdegree{}_f (\text{IF}_5 \; (g) ) + 2 \; \Delta H\textdegree{}_f (\text{IF} \; (g) ) - \Delta H\textdegree{}_f (\text{IF}_7 \; (g) ) - \Delta H\textdegree{}_f (\text{I}_2 \; (s) ) \\ = \Delta H\textdegree{}_{\text{rxn}}$

$\begin{array}{ccc} \Delta H\textdegree{}_f (\text{IF} \; (g) )& = & 1/2\; ( \Delta H\textdegree{}_{\text{rxn}} - \Delta H\textdegree{}_f (\text{IF}_5 \; (g) ) + \Delta H\textdegree{}_f (\text{IF}_7 \; (g) ) + \Delta H\textdegree{}_f (\text{I}_2 \; (s) ) )\\ & = & 1/2 \; (-89 - (-840) + (-941))}\\ & = & - 95 \; \text{kJ} \cdot \text{mol}^{-1} \end{array}$

Note, that iodine on the reactant side is stated as a gas in the equation given in the question whereas under standard conditions it is expected to be under the solid state; the $\Delta H\textdegree{} _f$ given in the question seemingly corresponds to the one in which the reactant iodine exists as a solid rather than as a gas. Evaluating the last expression using data from an external source

$\Delta H\textdegree{}_f (\text{I}_2 \; (g) ) = \Delta H\textdegree{}_f(\text{I}_2 \; (s)) + \Delta H\textdegree{}_{\text{sublimation}}(\text{I}_2) = 62.42 \; \text{kJ} \cdot \text{mol}^{-1}$ (Cox, Wagman, et al., 1984)

... yields $\Delta H\textdegree{}_f (\text{IF} \; (g) ) \approx -64 \; \text{kJ}\cdot \text{mol}^{-1}$ , which deviates significantly from the experimental value of $-94.76 \; \text{kJ}\cdot \text{mol}^{-1}$ (Chase, 1998.) It is thus assumed that the $\Delta H\textdegree{}_\text{rxn}$ value provided requires a reaction with $\text{I}_2 \; (s)$ rather than $\text{I}_2 \; (g)$ as a reactant.

3 0

3 years ago

Is lead a compound? State true or false

Mila [183]

False. Lead is not a compound, it is an element.

5 0

3 years ago

Read 2 more answers