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2 years ago

Which color changes represent a positive reaction for the presence of starch using the iodine test?

Chemistry

1 answer:

-BARSIC- [3]2 years ago

3 0

Looking at a ph level color chart, it should be moving to more acidic if it’s positive

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Quick question: Are water molecules attracted to each other because of the polar nature of water?

Colt1911 [192]

Answer:

Because the opposite charge between them

Explanation:

4 0

2 years ago

Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 5.90 moles of magnesium perchlorate, Mg(ClO4)2.

Lady bird [3.3K]

Answer:

5.90, 11.8, 47.2

Explanation:

Let’s remove the parentheses and write the formula as MgCl₂O₈.

We see that 1 mol Mg(ClO₄)₂ contains 1 mol Mg atoms, 2 mol Cl atoms, and 8 mol O atoms.

∴ $\text{Moles of Mg atoms} = \text{5.90 mol Mg(ClO}_{4})_{2} \times \frac{\text{1 mol Mg atoms}} {\text{1 mol Mg(ClO}_{4})_{2}} = \text{5.90 mol Mg atoms}$

$\text{Moles of Cl atoms} = \text{5.90 mol Mg(ClO}_{4})_{2} \times \frac{\text{2 mol Cl atoms}} {\text{1 mol Mg(ClO}_{4})_{2}} = \text{11.8 mol Cl atoms}$

$\text{Moles of O atoms} = \text{5.90 mol Mg(ClO}_{4})_{2} \times \frac{\text{8 mol O atoms}} {\text{1 mol Mg(ClO}_{4})_{2}} = \text{47.2 mol O atoms}$

∴ Mg, Cl, O = 5.90, 11.8, 47.2

4 0

2 years ago

For which of the following elements would the most common ion be expected to have a larger radius than that of its corresponding

Andre45 [30]

Answer: The ion that is expected to have a larger radius than the corresponding atom is chlorine.

Explanation:

There are two types of ions:

Cations: They are formed when an atom looses its valence electrons. They are positive ions.
Anions: They are formed when an atom gain electrons in its outermost shell. They are negative ions.

For positive ions, the removal of electron increases the nuclear charge for an outermost electron because the outermost electrons are more strongly attracted by the nucleus. So, the effective nuclear charge increases for cations and thus, the size of the cation will be smaller than that of the corresponding atom.

For negative ions, the addition of electron decreases the nuclear charge for an outermost electron because the outermost electrons are less strongly attracted by the nucleus. So, the effective nuclear charge decreases for anions and thus, the size of the anion will be larger than that of the corresponding atom.

For the given options:

Option a: Chlorine

Chlorine gains 1 electron and form $Cl^-$ ion

Option b: Sodium

Sodium looses 1 electron and form $Na^+$ ion

Option c: Copper

Copper looses 2 electrons and form $Cu^{2+}$ ion

Option d: Strontium

Strontium looses 2 electrons and form $Sr^{2+}$ ion

Hence, the ion that is expected to have a larger radius than the corresponding atom is chlorine.

8 0

2 years ago

Explain the way ammonia, salt, and water are alike

WARRIOR [948]

All of them are compounds.

3 0

2 years ago

Identify a predator from a Himalayan Mountain ecosystem. How else can this animal be classified in terms of feeding relationship

postnew [5]

Answer:

A snow leopard is one of the top consumers in the Himalayas who lives in dens that are close to somewhere to look down to watch its prey. They also use it's large paws to climb up slopes and snow and a long tale to balance on thin spaces to catch markhhors.

Explanation:

6 0

1 year ago