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3 years ago

How does water change as it freezes?

Chemistry

1 answer:

bagirrra123 [75]3 years ago

5 0

Answer:

Hi there!

Your answer is:

Explanation:

When frozen, water turns from a liquid to a solid! An example of this is a glass of water. You fill the glass with liquid tap water, and then put ice cubes in it. The ice cubes are solid and the tap water is liquid!

I hope this helps!

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An ate or ite at the end of a compound name usually indicates that the compound contains___________.

Ymorist [56]

Answer:

Explanation:

According to IUPAC nomenclature, a negative polyatomic ion has its name ending in 'ate' or 'ite'

As in carbonate (CO3^2-)

Arsenite (AsO3-)

3 0

3 years ago

Read 2 more answers

Consider the following reaction

Fynjy0 [20]

Answer:

92.72 kJ

Explanation:

2 N₂ (g) + O₂ (g) —-> 2 N₂O

According to question , one mole of N₂O requires 163.2 kJ of heat

Molecular weight of N₂O = 44 gm

25 g N₂O = 25 / 44 mole

25 / 44 mole will require 163.2 x 25 / 44 kJ

= 92.72 kJ

6 0

3 years ago

A sample of salt (sodium chloride) is placed on the tip of a platinum wire. When the sample is heated on blue flame the flame tu

gulaghasi [49]

So platinum is a transition metal. In general transition metals are reducers, which means they can give the electrons they have, to the sodium atoms. Also in chemistry we look at sub orbitals rather that shells(2,8,8). So due to the energy from heat, the d orbital split as electrons move to a higher energy level. Some of the electrons are given to the sodium ions and therefore the flame changes colour to yellow.
The excitation of the electrons is caused by them getting energy and so moving up an energy level. This energy is released and the electron returns to it's original state. The energy released, however, does not release in the same direction, but in different/various directions. Therefore the colour of the light changes as some energy is released in the surrounding.

8 0

3 years ago

1) A common experiment to determine the relative reactivity of metallic elements is to place a pure sample of one metal into an

Annette [7]

Answer: $Zn(s)+CuSO_4(aq)\rightarrow ZnSO_4+Cu$

Explanation:-

Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.

As zinc is more reactive than copper, it could easily displace copper from its aqueous solution and thus leads to formation of zinc (II) sulfate and pure copper.

The chemical reaction can be represented as :

$Zn(s)+CuSO_4(aq)\rightarrow ZnSO_4+Cu$

The phases are represented as (s) for solid sate, (l) for liquid state, (g) for gaseous state and (aq) for aqueous state.

7 0

3 years ago

Read 2 more answers

The following reactions can be used to prepare samples of metals. Determine the enthalpy change under standard state conditions

mamaluj [8]

Answer:

a) 62.1 kJ/mol

b) 2.82 kJ/mol

c) 270.91 kJ/mol

d) -851.5 kJ/mol

Explanation:

The enthalpy change for a reaction in standard conditions (ΔH°rxn) can be calculated by:

ΔH°rxn = ∑n*ΔH°f, products - ∑n*ΔH°f, reagents

Where n is the number of moles in the stoichiometry reaction, and ΔH°f is the enthalpy of formation at standard conditions. ΔH°f = 0 for substances formed by only a single element. The values can be found in thermodynamics tables.

a) 2Ag₂O(s) → 4Ag(s) + O₂(g)

ΔH°f, Ag₂O(s) = -31.05 kJ/mol

ΔH°rxn = 0 - (2*(-31.05)) = 62.1 kJ/mol

b) SnO(s) + CO(g) → Sn(s) + CO₂(g)

ΔH°f,SnO(s) = -285.8 kJ/mol

ΔH°f,CO(g) = -110.53 kJ/mol

ΔH°f,CO₂(g) = -393.51 kJ/mol

ΔH°rxn = [-393.51] - [-110.53 - 285.8] = 2.82 kJ/mol

c) Cr₂O₃(s) + 3H₂(g) → 2Cr(s) + 3H₂O(l)

ΔH°f,Cr₂O₃(s) = -1128.4 kJ/mol

ΔH°f,H₂O(l) = -285.83 kJ/mol

ΔH°rxn = [3*(-285.83)] - [( -1128.4)] = 270.91 kJ/mol

d) 2Al(s) + Fe₂O₃(s) → Al₂O₃(s) + 2Fe(s)

ΔH°f,Fe₂O₃(s) = -824.2 kJ/mol

ΔH°f,Al₂O₃(s) = -1675.7 kJ/mol

ΔH°rxn = [-1675.7] - [-824.2] = -851.5 kJ/mol

3 0

3 years ago