Are normal salts acidic, basic or neutral salt?

To test paint quality, scientists designed an experiment where the paint was exposed to temperatures ranging from 260 degrees Ce

pishuonlain [190]

Answer:

The independent variable is the temperature to which the paint and materials are exposed

The dependent variable is the presence of peeling and cracking of the paint

The constant rates are the paint and material used for each trial

Explanation:

The treatment the to which the paint is subjected = Temperatures from 260 °C to 650 °C

The method of determining the paint quality = By peeling and cracking

The types of paint and materials used = The same paint and material

The independent variable is the variable suspected as the cause of the effect being studied. It is the variable introduced as a treatment

In the question, given that the paint is subjected to different temperatures from between 260°C to 650 °C, the temperature changes introduced is the independent variable

Therefore;

The independent variable = The temperature to which the paint and materials are exposed to

The dependent variable is the effect variable. It is the variable of the property being investigated and it is also the variable that is measured in the investigation

In the question, given that the after heating the paint and material, the scientist check for peeling and cracking, the dependent variable is the occurrence of cracking and peeling at a given temperature

Therefore;

The dependent variable = The presence of peeling and cracking of the paint

The constant rate(s) are variables which are kept constant during the investigation, under the different treatments

The constant rate(s) in the tests are the paint and material, which were kept the same for each trial to reduce the effect of underlying factors that may impact on the result and obscure the relationship between the dependent and independent variables

Therefore;

The constant rate are the paint and material used for each trial

8 0

3 years ago

When 20.0 g of KI are dissolved in 50.0 mL of distilled water in a calorimeter, the temperature drops from 24.0 °C to 19.0 °C. C

Reil [10]

<h2>Answer:</h2>

<h2>Explanations</h2>

The formula for calculating the amount of heat absorbed by the water is given as:

$\begin{gathered} q=mc\triangle t \\ q=50\times4.18\frac{J}{g^oC}\times(19-24) \\ q=50\times4.18\times(-5) \\ q=-1045Joules \\ q=-1.045kJ \end{gathered}$

Determine the moles of KI

$\begin{gathered} moles\text{ of KI}=\frac{mass\text{ of KI}}{molar\text{ mass of KI}} \\ moles\text{ of KI}=\frac{20g}{166g\text{/mol}} \\ moles\text{ of KI}=0.1205moles \end{gathered}$

Since heat is lost, hence the enthalpy change of the solution will be negative that is:

$\begin{gathered} \triangle H=-q \\ \triangle H=-(-1.045kJ) \\ \triangle H=1.045kJ \end{gathered}$

Determine the enthalpy of solution in kJ•mol-1

$\begin{gathered} \triangle H_{diss}=\frac{1.045kJ}{0.1205mole} \\ \triangle H_{diss}\approx8.67kJmol^{-1} \end{gathered}$

Hence the enthalpy of solution in kJ•mol-1 for KI is 8.67kJ/mol

4 0

1 year ago

Aqueous hydrobromic acid (HBr) will react with solid sodium hydroxide (NaOH) to produce aqueous sodium bromide (NaBr) and liquid

bogdanovich [222]

Explanation:

Aqueous hydrobromic acid (HBr) will react with solid sodium hydroxide (NaOH) to produce aqueous sodium bromide (NaBr) and liquid water (H₂O). They will react according to the following equation.

HBr + NaOH ---> NaBr + H₂O

0.81 g of HBr are mixed with 0.568 g of NaOH. We have to find the mass of NaBr that can be produced. To do that we have to find which of the reactants is limiting the reaction. First, we will convert their grams into moles using their molar masses.

molar mass of HBr = 80.91 g/mol

molar mass of NaOH = 40.00 g/mol

mass of HBr = 0.81 g

mass of NaOH = 0.568 g

moles of HBr = 0.81 g * 1 mol/(80.91 g)

moles of HBr = 0.0100 moles

moles of NaOH = 0.568 g * 1 mol/(40.00 g)

moles of NaOH = 0.0142 moles

HBr + NaOH ---> NaBr + H₂O

Now if we take a quick look at the coefficients of the reaction we will see that 1 mol of HBr will react with 1 mol of NaOH since both coefficients are 1. Then their molar ratio is 1 : 1. That also means that 0.0100 moles of HBr will only react with 0.0100 moles of NaOH, and we have mixed 0.0142 moles of it. So, NaOH is in excess and HBr is the limiting reagent.

1 mol of HBr : 1 mol of NaOH molar ratio

moles of NaOH = 0.0100 moles of HBr * 1 mol of NaOH/(1 mol of HBr)

moles of NaOH = 0.0100 moles < 0.0142 moles ----> NaOH is in excess

And now that we know that HBr is the limiting reagent we can find the number of moles of NaBr that will be produced by 0.0100 moles of HBr. And finally convert those moles into grams using the molar mass.

1 mol of HBr : 1 mol of NaBr molar ratio

moles of NaBr = 0.0100 moles of HBr * 1 mol of NaBr/(1 mol of HBr)

moles of NaBr = 0.0100 moles

molar mass of NaBr = 102.89 g/mol

mass of NaBr = 0.0100 moles * 102.89 g/mol

mass of NaBr = 1.0289 g

mass of NaBr = 1.0 g

Answer: the maximum mass of sodium bromide that could be produced is 1.0 g.

7 0

1 year ago

If 8.23 g of magnesium chloride react completely with sodium phosphate, how many grams of magnesium phosphateare produced

steposvetlana [31]

Answer:

The correct answer is 7.57 grams of magnesium phosphate.

Explanation:

Based on the given question, the chemical reaction taking place is:

2Na₃PO₄ (aq) + 3MgCl₂ (aq) ⇒ Mg₃(PO₄)2 (s) + 6NaCl (aq)

From the given reaction, it is evident that two moles of sodium phosphate reacts with three moles of magnesium chloride to produce one mole of magnesium phosphate.

Based on the given information, 8.23 grams of magnesium chloride reacts completely with sodium phosphate, therefore, magnesium chloride in the given case is the limiting reagent.

In the given case, 3 moles of magnesium chloride produce 1 mole of magnesium phosphate. Therefore, 1 mole of magnesium chloride will produce 1/3 mole of magnesium phosphate.

The molecular mass of magnesium chloride is 95.21 grams per mole. So, 1 mole of magnesium chloride is equivalent to 95.21 grams of magnesium chloride.

On the other hand, the molecular mass of magnesium phosphate is 262.85 grams per mole. Therefore, 1 mole of magnesium phosphate is equal to 262.85 grams of magnesium phosphate.

As seen earlier that 1 mole of magnesium chloride = 1/3 moles of magnesium phosphate. So,

95.21 grams of magnesium chloride = 1/3 × 262.85 grams of magnesium phosphate

= 262.85 / 3 grams of magnesium phosphate

1 gram of magnesium chloride = 262.85 / 3 × 95.21 grams of magnesium phosphate

8.23 grams of magnesium chloride = 262.85 / 3 × 95.21 × 8.23 grams of magnesium phosphate

= 7.57 grams of magnesium phosphate

Hence, when 8.23 grams of magnesium chloride when reacts completely with sodium phosphate, it produces 7.57 grams of magnesium phosphate.

8 0

3 years ago

Salt and pepper are placed in a jar and the jar is shaken. What has formed?

victus00 [196]

Answer:

a negative charge

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7 0

2 years ago

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