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3 years ago

When you blow dry your hair

2 answers:

4 0

Any change that occurs without altering the chemical composition of a substance is a physical change. Physical changes can include changing the color, shape, state of matter, or volume of a substance
A usually irreversible chemical reaction involving the rearrangement of the atoms of one or more substances and a change in their chemical properties or composition, resulting in the formation of at least one new substance: The formation of rust on iron is a chemical change.

The answers to the questions are :
Physical
Chemical
Chemical
Chemical
Chemical
Chemical

mixer [17]3 years ago

3 0

In short a physical change is something that changed the way something looks but doesn't affect the chemical makeup. Drying your hair doesn't change the color of your hair, it just makes it dry so thats a physical change. Rust forming on a knife is a chemical change becaause the water reacts with the chemical makeup of the knife. Hope that helps.

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Which statement is true of a heterogeneous mixture but not of a

Natalka [10]

Answer:

Explanation:

well heterogenous mixtures are not uniformly distributed these meaning whatever components are "mixed" can be seperated easily

a example of this can be

Soil, oil in water, ice in water

while Homogeneous mixture cannot be seen seperated

4 0

3 years ago

90 POINTSSSS!!!

Katarina [22]

Answer:

$\large \boxed{\text{-2043.96 kJ/mol}}$

Explanation:

Assume the reaction is the combustion of propane.

Word equation: propane plus oxygen produces carbon dioxide and water

Chemical eqn: C₃H₈(g) + O₂(g) ⟶ CO₂(g) + H₂O(g)

Balanced eqn: C₃H₈(g) + 5O₂(g) ⟶ 3CO₂(g) + 4H₂O(g)

(a) Table of enthalpies of formation of reactants and products

$\begin{array}{cc}\textbf{Substance} & \textbf{$\Delta_{\text{f}}$H/(kJ/mol}) \\\text{C$_{3}$H$_{8}$(g)} & -103.85 \\\text{O}_{2}\text{(g)} & 0 \\\text{CO}_{2}\text{(g)} & -393.51 \\\text{H$_{2}$O(g)} & -241.82\\\end{array}$

(b)Total enthalpies of reactants and products

$\Delta_{\text{rxn}}H^{\circ} = \sum \left( \Delta_{\text{f}} H^{\circ} \text{products}\right) - \sum \left (\Delta_{\text{f}}H^{\circ} \text{reactants} \right)\\= \text{-2147.81 kJ/mol - (-103.85 kJ/mol)}\\= \text{-2147.81 kJ/mol + 103.85 kJ/mol}\\= \textbf{-2043.96 kJ/mol}\\\text{The enthalpy change is $\large \boxed{\textbf{-2043.96 kJ/mol}}$}$

ΔᵣH° is negative, so the reaction is exothermic.

5 0

3 years ago

Substance A and B are chemically exactly the same. The molecules in substance A move much faster and are less ordered than the m

Elina [12.6K]

Answer:

substance A is a liquid, while substance B is a liquid or gas

7 0

3 years ago

Read 2 more answers

Can you tell me name of Chemicals in food?

Artyom0805 [142]

Answer:

Guar gum

sodium nitrite

artificial food colorings

monosodium glutamate

etc

6 0

2 years ago

Precipitation reactions always occur when two aqueous solutions are mixed (T/F)

Studentka2010 [4]

Answer: The given statement is false.

Explanation:

Precipitation reaction is defined as the chemical reaction in which two aqueous solution upon mixing together results in the formation of an insoluble solid.

For example, $NaCl(aq) + AgNO_{3} \rightarrow NaNO_{3}(aq) + AgCl(s)$

Here AgCl is present in solid state so, it is the precipitate.

But it is not necessarily true that two aqueous solutions will always result in the formation of a precipitate.

For example, $NaCl(aq) + KNO_{3}(aq) \rightarrow KCl(aq) + NaNO_{3}(aq)$

Hence, we can conclude that the statement precipitation reactions always occur when two aqueous solutions are mixed, is false.

7 0

3 years ago