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3 years ago

Question 8

Chemistry

1 answer:

castortr0y [4]3 years ago

5 0

Answer:

The 5 chemical changes are. 1) Tarnish, 2) Rust, 3) Dissolve, 4) Burn, 5) Bake.

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element x is a neutral element and has 39 protons. what element is it and how many electrons does it have? (use the periodic tab

alisha [4.7K]

The element itself is Yttrium, which is a transition metal and not that reactive. Since it has 39 protons it will also have 39 electrons.

4 0

3 years ago

Write down any two test for the CH2=CH2[ethene]

Assoli18 [71]

Answer:

a) Linear polymerization

b) cyclic polymerization

7 0

3 years ago

Table salt is sodium chloride and has the chemical formula of NaCl. What is the ratio of sodium atoms to chlorine atoms? (8.5D)

astra-53 [7]

Answer:

Explanation:Table salt is sodium chloride and has the chemical formula of NaCl. What is the ratio of sodium atoms to chlorine atoms? (8.5D)

Answer

А 2:1

1:1

1:2

3:1

7 0

2 years ago

The thin outer layer of Earth, called the crust, contains only 0.50 percent of Earth's total mass and yet is the source of almos

Rzqust [24]

Answer:

The mass of silicon in kilograms in Earth's crust is $7.2729\times 10^{21} kg$ .

Explanation:

Mass of Earth = $5.9\times 10^{21} tons$

(1 ton= 2000 lb)

(1 lb =453.6 g)

1 ton = 2000 × 453.6 g =907,200 g

Mass of Earth = $5.9\times 10^{21}\times 907,200 g=5.3524\times 10^{27} g$

Percentage of earth crust = 0.50%

Mass of earth crust = M

$0.50\%=\frac{M}{5.3524\times 10^{27}}\times 100$

$M=2.6762\times 10^{25} g$

Percentage of the silicon in Earth's crust = 27.2 %

Mass of silicon in in Earth's crust = m

$Si\%=\frac{m}{M}\times 100$

$27.2\%=\frac{m}{2.6762\times 10^{25} g}\times 100$

$m = 7.2792\times 10^{24} g=7.2729\times 10^{21} kg$

1000 g = 1 kg

The mass of silicon in kilograms in Earth's crust is $7.2729\times 10^{21} kg$ .

7 0

3 years ago

You have an aqueous solution of chromium(III) nitrate that you titrate with an aqueous solution of sodium hydroxide. After a cer

barxatty [35]

Answer:

The precipitate was chromium hydroxide, which then reacted with more hydroxide to produce a soluble complex, Cr(OH)4

Explanation:

The following reaction takes place when chromium(III) nitrate reacts with NaOH:

$Cr(NO)_{3}$ +3 NaOH → $Cr(OH)_{3}$ (s)+ $NaNO_{3}$

The precipitate that is formed is chromium hydroxide, $Cr(OH)_{3}$

When more NaOH is added, the precipitate reacts with it which then results in the formation of a soluble complex ion:

$Cr(OH)_{3}$ (s) + $OH^{-}$ (aq) → $Cr(OH)_{4} ^{-}$ (aq)

$Cr(OH)_{4} ^{-}$ is soluble complex ion

7 0

3 years ago