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1 year ago

Help Me Please Thank You

Chemistry

2 answers:

Maurinko [17]1 year ago

7 0

For quest or 4 it would be C. Im cant see all the answers on 5 so I’m not sure sorru

NISA [10]1 year ago

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The Gulf Stream, warm current in the Atlantic

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Which option(s) correctly shows an anion? Select all that apply.

nata0808 [166]

Answer:

Explanation:

becaue neutron equal to mass num -atomic num

7 0

3 years ago

What mass of HCL, in grams, is required to react with 0.610 g of al(oh)3 ?

kompoz [17]

Answer: 0.8541 grams of HCl will be required.

Explanation: Moles can be calculated by using the formula:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of $Al(OH)_3$ = 0.610 g

Molar mass of $Al(OH)_3$ = 78 g/mol

$\text{Number of moles}=\frac{0.610g}{78g/mol}$

Number of moles of $Al(OH)_3$ = 0.0078 moles

The reaction between $Al(OH)_3$ and HCl is a type of neutralization reaction because here acid and base are reacting to form an salt and also releases water.

Chemical equation for the above reaction follows:

$Al(OH)_3+3HCl\rightarrow AlCl_3+3H_2O$

By Stoichiometry,

1 mole of $Al(OH)_3$ reacts with 3 moles of HCl

So, 0.0078 moles of $Al(OH)_3$ will react with $\frac{3}{1}\times 0.0078$ = 0.0234 moles

Mass of HCl is calculated by using the mole formula, we get

Molar mass of HCl = 36.5 g/mol

Putting values in the equation, we get

$0.0234moles=\frac{\text{Given mass}}{36.5g/mol}$

Mass of HCl required will be = 0.8541 grams

3 0

3 years ago

1. Calculate the attractive bonding force for NaF and for MgO when the ions just touch. Based on the attractive bonding force, w

Andreas93 [3]

Answer:

The attractive force is negative and MgO has a higher melting point

Explanation:

From Couloumb's law:

Energy of interaction, E = k $\frac{q1q2}{r}$

where q1 and q2 are the charges of the ions, k is Coulomb's constant and r is the distance between both ions, i.e the atomic radii of the ions.

If you look at Coulomb's law, you note that in the force is negative (because q1 is negative while q2 is positive).

In addition to that, the compounds MgO and NaF have similar combined ionic radii, then we can determine the melting point trend from the amount of energy gotten

The melting point of ionic compounds is determined by 1. charge on the ions 2. size of ions. while NaF has smaller charges (+1 and -1), MgO (+2 and -2) has larger charges and greater combined atomic radii. This implies that the compound with greater force would have a higher melting point.

Hence the compound MgO would have a higher melting point than NaF.

5 0

3 years ago

The source of bitterness in dark chocolate is the compound theobromine, an alkaloid present in cocoa beans. In a sample of dark

spin [16.1K]

Answer: 193 mg of theobromine are present in the sample.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given molecules}}{\text {Avogadros number}}=\frac{6.45\times 10^{20}}{6.023\times 10^{23}}=1.07\times 10^{-3}moles$

1 mole of theobromine $(C_7H_8N_4O_2)$ weigh = 180 g

$1.07\times 10^{-3}moles$ of theobromine $(C_7H_8N_4O_2)$ weigh = $\frac{180}{1}\times 1.07\times 10^{-3}=0.193g=193mg$ (1g=1000mg)

193 mg of theobromine are present in the sample.

5 0

3 years ago

Given the balanced equation representing a reaction: H2 → H + H What occurs during this reaction? 1. Energy is absorbed as bonds

RoseWind [281]

Answer : The correct option is, (2) Energy is absorbed as bonds are broken.

Explanation :

As we know that the bonds are formed and breaks during the chemical reaction. Some energy is released or absorbed when the bonds are formed and breaks during the chemical reaction.

During the bond breaking, some energy is required to break the bonds.

During the bond formation, some energy is released to the formation of the bonds.

In the given reaction, the bond between the hydrogen-hydrogen in $H_2$ are breaking into two hydrogen. That means during the bond breaking, some energy is required or absorbed to break the bonds.

Hence, the correct option is, (2) Energy is absorbed as bonds are broken.

8 0

2 years ago

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