We will get the molality from this formula:
Molality = no.of moles of solute / Kg of solvent
So first we need the no.of moles of KNO3 = the mass of KNO3 / molar mass of KNO3
no.of moles of KNO3 = 175 / 101.01 = 1.73 mol
By substitution in the molality formula:
∴ molality = 1.73 / (750/1000) = 2.3 Molal
The change in temperature of the metal is 6.1°C. Details about change in temperature can be found below.
<h3>How to calculate change in temperature?</h3>
The change in temperature of a substance can be calculated by subtracting the initial temperature of the substance from the final temperature.
According to this question, a 25.0 g sample of metal at 16.0 °C is warmed to 22.1 °C by 259J of energy.
This means that the change in temperature of the metal can be calculated as:
∆T = 22.1°C - 16°C
∆T = 6.1°C
Therefore, the change in temperature of the metal is 6.1°C.
Learn more about change in temperature at: brainly.com/question/19051558
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The answer is chemical weathering
First we need to find the number of moles that 43.9g of gallium metal is. We can do this by finding the molar weight of gallium and cross-multiplying to cancel out units:
So we are dealing with 0.63 moles of gallium metal.
We can take from the balanced equation that 4 moles of gallium metal will react completely with 3 moles of oxygen gas. We can take this ratio and make a proportion to find the amount of oxygen gas, in moles, that will react completely with 0.63 moles of gallium metal:
Cross multiply and solve for x:
So now we know that 0.47 moles of oxygen gas will react with 43.9g of gallium metal.
There should be 3 valence electrons surrounding the aluminum ion