The opening session of the Scottish Parliament was largely devoted to ceremony, including swearing in MSPs and electing the presiding officer.
Members found time to lodge 51 questions and motions - 28 of them from Willie Rennie on the China agreement.
There was controversy about the issue during the election campaign.
It emerged during the election period that First Minister Nicola Sturgeon had signed the memorandum, potentially worth up to Â£10bn of investment, with SinoFortone and China Railway No 3 Engineering Group.
At the time, Lib Dem leader Mr Rennie called for the agreement to be torn up after a parent firm of the engineering group had been blacklisted by Norway's state pension fund over fears of "gross corruption". Fears have also been voiced about human rights abuses.
Ms Sturgeon said no firm investment plans had been made and insisted that due diligence would be carried out, although a UK advisor to the Chinese firms said specific projects had been discussed and claimed Ms Sturgeon wanted work to begin "this year".
Mr Rennie lodged a total of 28 questions, all on the topic of the China agreement and government memoranda of understanding.
He asked a series of questions about whether government officials were aware of the Norwegian blacklisting, their assessment of the firm's human rights record, what advice was taken before signing the memorandum, and whether the government would suspend the memorandum until it had investigated concerns.
The Scottish Parliament website indicated that the questions were likely to be answered on 26 May.
Ms Sturgeon has previously said that "if there were any concerns that said these were deals we should not do, then we wouldn't do them".
A number of other MSPs also lodged questions on their first day back at work after the election.
Labour MSP Neil Findlay submitted three motions, one of them on the "growing number of Scottish citizens identified as being involved in undercover policing scandals".
His motion calls on the UK government to extend the Pitchford inquiry into undercover policing into Scotland, and says that if it does not, the Scottish government should set up an inquiry of its own.
Mr Findlay also submitted a motion to welcome the verdict of the Hillsborough inquests, and another calling for directors of companies that take part in blacklisting to be tried in court.
Green MSP Mark Ruskell, who has now returned to parliament having lost his seat in 2011, lodged 13 questions on his first day back in the job.
Mr Ruskell's questions focused on a series of environmental issues, including the culling of mountain hares and the reintroduction of beavers to Scotland.

The 19-year-old striker is yet to make a senior appearance for Everton but twice featured in the Premier League club's Under-23 side that played in the EFL Trophy this season.
Southport-born Brewster, an Everton academy player since he was 12, had a previous loan spell at Stockport.
He is available to make his Southport debut against Wrexham on Sunday.
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Dozens of questions about the Scottish government memorandum of understanding with Chinese firms were lodged during the first session at Holyrood.
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Everton teenager Delial Brewster has joined National League side Southport on loan until the end of the season.